Updated on 2024/03/03

写真a

 
TSURUTA Kenji
 
Organization
Faculty of Environmental, Life, Natural Science and Technology Professor
Position
Professor
External link

Degree

  • Doctor of Science ( 1994.3   The University of Tokyo )

  • Master of Science ( 1991.3   The University of Tokyo )

Research Interests

  • Device Physics

  • Nanomateirlals/Nanodevices

  • Multiscale Simulation

  • Topological Phononics

  • Metamaterial

Research Areas

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Electric and electronic materials

  • Nanotechnology/Materials / Nano/micro-systems

  • Nanotechnology/Materials / Nanomaterials

  • Nanotechnology/Materials / Nanostructural physics

  • Nanotechnology/Materials / Applied condensed matter physics

Education

  • The University of Tokyo   理学系研究科   物理学

    - 1994

      More details

    Country: Japan

    researchmap

  • The University of Tokyo    

    - 1994

      More details

Research History

  • Okayama University   Faculty of Environmental, Life, Natudal Science and Technology   Professor

    2023.4

      More details

  • Kyoto University   Research Base on "Elements Strategy Initiative for Structural Materials"   Project Professor

    2014 - 2022.3

      More details

  • Okayama University   Graduate School of Natural Science and Technology   Professor

    2011.4 - 2023.3

      More details

  • Kumamoto University   Graduate School of Science and Technology   Visiting Professor

    2011 - 2012

      More details

  • Niigata University   Graduate School of Science and Technology   Visiting Associate Professor

    2008 - 2011

      More details

  • Okayama University   Graduate School of Natural Science and Technology   Associate Professor

    2007 - 2011

      More details

  • Okayama University   Graduate School of Natural Science and Technology   Associate Professor

    2005 - 2007

      More details

  • Okayama University   Faculty of Engineering   Associate Professor

    2001 - 2005

      More details

  • Okayama University   Faculty of Engineering   Senior Assistant Professor

    1998 - 2001

      More details

  • Louisiana State University   Department of Physics and Astronomy, Concurrent Computing Laboratory for Materials SImulation   Posctodoctoral Research Associate

    1994.11 - 1998.3

      More details

    Country:United States

    researchmap

  • Louisiana State University (U.S.A.)   Department of Physics and Astronomy   Researcher

    1994.11 - 1998.3

      More details

    Country:United States

  • Japan Society for Promotion of Science   Posctodoctoral Researcher

    1993.4 - 1994.10

      More details

  • University of California at San Diego   Department of Physics   Visiting Researcher

    1989 - 1990

      More details

    Country:United States

    researchmap

▼display all

Professional Memberships

▼display all

 

Papers

  • Active control of localized mode and transmission in topological phononic waveguides by non-Hermitian modulation Reviewed

    Md. Shuzon Ali, Yusuke Hata, Kenji Tsuruta

    Applied Physics Express   2023.9

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.35848/1882-0786/acf1ef

    researchmap

  • Reconfigurable waveguide based on valley topological phononic crystals with local symmetry inversion via continuous translation Reviewed

    Md. Shuzon Ali, Motoki Kataoka, Masaaki Misawa, Kenji Tsuruta

    Japanese Journal of Applied Physics   62 ( SJ )   SJ1002 - SJ1002   2023.7

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:IOP Publishing  

    Abstract

    We proposed a reconfigurable valley topological acoustic waveguide constructed using a 2D phononic crystal (PnC) with C3v symmetric arrangement of three rods in the unit cell. An interface between two types of PnCs with differently oriented unit cells exhibits high robustness of the valley transport of acoustic waves via the topologically protected state. Structural reconfiguration was introduced by the continuous translation of rod arrays in the PnCs. The topological phase transition in this translational change was quantitatively identified by the change in the Berry curvature. The translation of the rods leaves a dimer array at the interface, creating a localized/defective mode along the waveguide. Despite the presence of the localized mode, the acoustic wave can propagate along the reconfigurable waveguide the same as the original waveguide. The continuous translation of a rod array can be used to turn on and off the bandgap. This can be a new approach to design a robust acoustic device with a high reconfigurability.

    DOI: 10.35848/1347-4065/acae63

    researchmap

    Other Link: https://iopscience.iop.org/article/10.35848/1347-4065/acae63/pdf

  • Acoustic metasurfaces and topological phononics for acoustic/elastic device design Invited Reviewed

    Kenji Tsuruta

    Japanese Journal of Applied Physics   2023.7

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.35848/1347-4065/acc6da

    researchmap

  • Intermediate State between MoSe2 and Janus MoSeS during Atomic Substitution Process Reviewed

    Hiroo Suzuki, Yijun Liu, Masaaki Misawa, Chiyu Nakano, Yingzhe Wang, Ryo Nakano, Kentaro Ishimura, Kenji Tsuruta, Yasuhiko Hayashi

    Nano Letters   2023.5

     More details

    Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acs.nanolett.3c00972

    researchmap

  • Self-Limiting Growth of Monolayer Tungsten Disulfide Nanoribbons on Tungsten Oxide Nanowires Reviewed

    Hiroo Suzuki, Misaki Kishibuchi, Masaaki Misawa, Kazuma Shimogami, Soya Ochiai, Takahiro Kokura, Yijun Liu, Ryoki Hashimoto, Zheng Liu, Kenji Tsuruta, Yasumitsu Miyata, Yasuhiko Hayashi

    ACS Nano   2023.5

     More details

    Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acsnano.3c01608

    researchmap

  • Design and Robustness Evaluation of Valley Topological Elastic Wave Propagation in a Thin Plate with Phononic Structure Reviewed

    Motoki Kataoka, Masaaki Misawa, Kenji Tsuruta

    Symmetry   14 ( 10 )   2022.10

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)  

    Based on the concept of band topology in phonon dispersion, we designed a topological phononic crystal in a thin plate for developing an efficient elastic waveguide. Despite that various topological phononic structures have been actively proposed, a quantitative design strategy of the phononic band and its robustness assessment in an elastic regime are still missing, hampering the realization of topological acoustic devices. We adopted a snowflake-like structure for the crystal unit cell and determined the optimal structure that exhibited the topological phase transition of the planar phononic crystal by changing the unit cell structure. The bandgap width could be adjusted by varying the length of the snow-side branch, and a topological phase transition occurred in the unit cell structure with threefold rotational symmetry. Elastic waveguides based on edge modes appearing at interfaces between crystals with different band topologies were designed, and their transmission efficiencies were evaluated numerically and experimentally. The results demonstrate the robustness of the elastic wave propagation in thin plates. Moreover, we experimentally estimated the backscattering length, which measures the robustness of the topologically protected propagating states against structural inhomogeneities. The results quantitatively indicated that degradation of the immunization against the backscattering occurs predominantly at the corners in the waveguides, indicating that the edge mode observed is a relatively weak topological state.

    DOI: 10.3390/sym14102133

    Scopus

    researchmap

  • First-principles analysis of stearic acid adsorption on calcite (104) surface Reviewed

    Narumi Machida, Masaaki Misawa, Yuki Kezuka, Kenji Tsuruta

    e-Journal of Surface Science and Nanotechnology   20 ( 4 )   261 - 265   2022.8

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    DOI: 10.1380/ejssnt.2022-041

    researchmap

  • Surface Diffusion-Limited Growth of Large and High-Quality Monolayer Transition Metal Dichalcogenides in Confined Space of Microreactor. Reviewed International journal

    Hiroo Suzuki, Ryoki Hashimoto, Masaaki Misawa, Yijun Liu, Misaki Kishibuchi, Kentaro Ishimura, Kenji Tsuruta, Yasumitsu Miyata, Yasuhiko Hayashi

    ACS nano   2022.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Transition metal dichalcogenides (TMDCs), including MoS2 and WS2, are potential candidates for next-generation semiconducting materials owing to their atomically thin structure and strong optoelectrical responses, which allow for flexible optoelectronic applications. Monolayer TMDCs have been grown utilizing chemical vapor deposition (CVD) techniques. Enhancing the domain size with high crystallinity and forming heterostructures are important topics for practical applications. In this study, the size of monolayer WS2 increased via the vapor-liquid-solid growth-based CVD technique utilizing the confined space of the substrate-stacked microreactor. The use of spin-coated metal salts (Na2WO4 and Na2MoO4) and organosulfur vapor allowed us to precisely control the source supply and investigate the growth in a systematic manner. We obtained a relatively low activation energy for growth (1.02 eV), which is consistent with the surface diffusion-limited growth regime observed in the confined space. Through systematic photoluminescence (PL) analysis, we determined that a growth temperature of ∼820 °C is optimal for producing high-quality WS2 with a narrow PL peak width (∼35 meV). By controlling the source balance of W and S, we obtained large-sized fully monolayered WS2 (∼560 μm) and monolayer WS2 with bilayer spots (∼1100 μm). Combining two distinct sources of transition metals, WS2/MoS2 lateral heterostructures were successfully created. In electrical transport measurements, the monolayer WS2 grown under optimal conditions has a high on-current (∼70 μA/μm), on/off ratio (∼5 × 108), and a field-effect mobility of ∼7 cm2/(V s). The field-effect transistor displayed an intrinsic photoresponse with wavelength selectivity that originated from the photoexcited carriers.

    DOI: 10.1021/acsnano.2c05076

    PubMed

    researchmap

  • Numerical and experimental analysis of additively manufactured particle dampers at low frequencies Reviewed

    Honghu Guo, Kazuo Ichikawa, Hiroyuki Sakai, Heng Zhang, Xiaopeng Zhang, Kenji Tsuruta, Kanjuro Makihara, Akihiro Takezawa

    Powder Technology   396   696 - 709   2022.1

     More details

    Publishing type:Research paper (scientific journal)  

    Particle damping is an effective method for increasing structural damping and is utilized in many fields. Using laser powder bed fusion (LPBF) additive manufacturing (AM), a new integrated particle damper can be produced by deliberately leaving unfused powder inside the structure. This study focuses on experimentally and numerically investigating the damping mechanism and performance of additively manufactured particle dampers in the low-frequency range (< 100 Hz). A numerical simulation approach based on the discrete element method was developed to predict the damping performance of a particle damper. To reduce the computational cost, a multi-unit particle damper (MUPD) was introduced. A series of particle dampers of 316 L stainless steel with different numbers and sizes of unit cells were built using LPBF. The damping mechanism and performance of additively manufactured MUPDs (AM-MUPD) were studied, the results cross-verified via experiments and simulations, and the effects of unit cell size and number investigated.

    DOI: 10.1016/j.powtec.2021.11.029

    Scopus

    researchmap

  • Design of High-efficiency Sound Absorption and Energy Harvesting Devices Using Acoustic Metasurfaces Reviewed

    R. Takami, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2021)   42   3Pb4-7   2021.10

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Design and measurement of topological elastic waveguide based on phononic crystal Reviewed

    M. Kataoka, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2021)   42   1J1-1   2021.10

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Band Structure Design for a Two-Dimensional Phononic Crystal using Various Optimization Methods Reviewed

    K. Akae, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2021)   42   2Pa1-3   2021.10

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Design of topological phononic structure for multimode propagation Reviewed

    H. Takeshita, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2021)   42   3Pb1-2   2021.10

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Photoinduced oxygen transport in cobalt double-perovskite crystal EuBaCo2O5.39 Reviewed

    Masaki Hada, Satoshi Ohmura, Tadahiko Ishikawa, Masaki Saigo, Naoya Keio, Wataru Yajima, Tatsuya Suzuki, Daisuke Urushihara, Kou Takubo, Yusuke Masaki, Makoto Kuwahara, Kenji Tsuruta, Yasuhiko Hayashi, Jiro Matsuo, Takayoshi Yokoya, Ken Onda, Fuyuki Shimojo, Muneaki Hase, Sumio Ishihara, Toru Asaka, Nobuyuki Abe, Taka-hisa Arima, Shin-ya Koshihara, Yoichi Okimoto

    Applied Materials Today   24   101167 - 101167   2021.9

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.apmt.2021.101167

    researchmap

  • Low-frequency sound absorbing metasurface using multilayer split resonators Reviewed

    Shota Takasugi, Keita Watanabe, Masaaki Misawa, Kenji Tsuruta

    Japanese Journal of Applied Physics   60 ( {SD} )   2021.7

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:{IOP} Publishing  

    DOI: 10.35848/1347-4065/abe2e5

    researchmap

  • Optimization of molecular characteristics via machine learning based on continuous representation of molecules Reviewed

    Kyosuke Sato, Kenji Tsuruta

    Materials Science Forum   1016 MSF   1492 - 1496   2021

     More details

    Authorship:Corresponding author   Publishing type:Research paper (international conference proceedings)  

    We demonstrate an automatic materials design method using continuous representation of molecule and its atomic arrangement via a neural network algorithm. This method is applied to optimizing and predicting the HOMO-LUMO gap within the molecules composed of carbon, oxygen, nitrogen, fluorine, and hydrogen. Adopting the Quantum Machine 9 (QM9) dataset as a training dataset for the molecules, we first established a continuous representation of molecules in a latent space, then predicted molecules that have target values of the HOMO-LUMO gap. In the gap maximization calculation, CF4 with the largest gap value in the QM9 dataset was automatically found despite there is no a priori data for the gap. In the case of a target gap value of 0.10 hartree, we found a new molecule whose gap value is closer to 0.10 hartree than any other molecules in the QM9 dataset.

    DOI: 10.4028/www.scientific.net/MSF.1016.1492

    Scopus

    researchmap

  • A mechanistic investigation of moisture-induced degradation of methylammonium lead iodide Reviewed

    Masaki Hada, Md. Abdullah Al Asad, Masaaki Misawa, Yoichi Hasegawa, Ryota Nagaoka, Hiroo Suzuki, Ryuji Mishima, Hiromi Ota, Takeshi Nishikawa, Yoshifumi Yamashita, Yasuhiko Hayashi, Kenji Tsuruta

    Applied Physics Letters   117 ( 25 )   253304 - 253304   2020.12

     More details

    Publishing type:Research paper (scientific journal)   Publisher:AIP Publishing  

    DOI: 10.1063/5.0021338

    researchmap

  • Parameter optimisation for phononic structure using CMA-ES and S-matrix Reviewed

    Hiroshi ISAKARI, Kei MATSUSHIMA, Kenji TSURUTA, Toru TAKAHASHI, Toshiro MATSUMOTO

    Transactions of the Japan Society for Computational Methods in Engineering   20   65 - 73   2020.12

     More details

    Language:Japanese   Publishing type:Research paper (scientific journal)  

  • Low-frequency sound absorbing metasurface using multiple split resonators Reviewed

    S. Takasugi, K. Watanabe, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2020)   41   3Pb1-1   2020.11

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Reconfigurable valley topological phononic waveguide with local C3v symmetry Reviewed

    K. Okuno, M. Misawa, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2020)   41   3Pa1-2   2020.11

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Super-chiral vibrational spectroscopy with metasurfaces for high-sensitive identification of alanine enantiomers Reviewed

    Takumi Iida, Atsushi Ishikawa, Takuo Tanaka, Atsuya Muranaka, Masanobu Uchiyama, Yasuhiko Hayashi, Kenji Tsuruta

    Applied Physics Letters   117 ( 10 )   101103 - 101103   2020.9

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:AIP Publishing  

    DOI: 10.1063/5.0012331

    researchmap

  • Topologically robust sound wave transport in two-dimensional phononic crystal with a circular rod arrangement in water Reviewed

    Kenshi Okuno, Kenji Tsuruta

    Japanese Journal of Applied Physics   59   2020.7

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:{IOP} Publishing  

    DOI: 10.35848/1347-4065/ab7c0e

    Scopus

    researchmap

  • Design of non-circular membranes metasurfaces for broadband sound absorption Reviewed

    Keita Watanabe, Mikiya Fujita, Kenji Tsuruta

    Japanese Journal of Applied Physics   59   2020.7

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:{IOP} Publishing  

    DOI: 10.35848/1347-4065/ab7e3e

    Scopus

    researchmap

  • Characterization of the Σ5(210) / [001] Grain Boundary of Methyl-Ammonium Lead Triiodide Perovskite using Density Functional Theory Reviewed

    Kenji TSURUTA

    Transactions of the Materials Research Society of Japan   2020.6

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.14723/tmrsj.45.67

    researchmap

  • Liquid-like dielectric response is an origin of long polaron lifetime exceeding 10 μs in lead bromide perovskites Reviewed

    Kiyoshi Miyata, Ryota Nagaoka, Masaki Hada, Takanori Tanaka, Ryuji Mishima, Taihei Kuroda, Sota Sueta, Takumi Iida, Yoshifumi Yamashita, Takeshi Nishikawa, Kenji Tsuruta, Yasuhiko Hayashi, Ken Onda, Toshihiko Kiwa, Takashi Teranishi

    The Journal of Chemical Physics   152 ( 8 )   084704 - 084704   2020.2

     More details

    Publishing type:Research paper (scientific journal)   Publisher:AIP Publishing  

    DOI: 10.1063/1.5127993

    researchmap

  • Whitish daytime radiative cooling using diffuse reflection of non-resonant silica nanoshells Reviewed

    Suichi, T., Ishikawa, A., Tanaka, T., Hayashi, Y., Tsuruta, K.

    Scientific Reports   10 ( 1 )   2020

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41598-020-63591-7

    Scopus

    researchmap

  • Design of Non-circular Membranes Metasurfaces for Broadband Sound Absorption Reviewed

    K. Watanabe, M. Fujita, and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2019)   40   2P1-5   2019.11

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Topologically robust sound wave transport using phononic crystal in water Reviewed

    K. Okuno and K. Tsuruta

    Proceedings of Symposium on Ultrasonic Electronics (USE2019)   40   2P1-4   2019.11

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Ultrafast isomerization-induced cooperative motions to higher molecular orientation in smectic liquid-crystalline azobenzene molecules Reviewed

    M. Hada, D. Yamaguchi, T. Ishikawa, T. Sawa, K. Tsuruta, K. Ishikawa, S. Koshihara, Y. Hayashi, T. Kato

    Nature Communications   10 ( 1 )   4159 - 4159   2019.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41467-019-12116-6

    Scopus

    researchmap

  • Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode Reviewed

    Masaki Hada, Kiyoshi Miyata, Satoshi Ohmura, Yusuke Arashida, Kohei Ichiyanagi, Ikufumi Katayama, Takayuki Suzuki, Wang Chen, Shota Mizote, Takayoshi Sawa, Takayoshi Yokoya, Toshio Seki, Jiro Matsuo, Tomoharu Tokunaga, Chihiro Itoh, Kenji Tsuruta, Ryo Fukaya, Shunsuke Nozawa, Shin-ichi Adachi, Jun Takeda, Ken Onda, Shin-ya Koshihara, Yasuhiko Hayashi, Yuta Nishina

    ACS Nano 2019   Vol.13 ( 9 )   10103 - 10112   2019.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACS Publications  

    A two-dimensional nanocarbon, graphene, has attracted substantial interest due to its excellent properties. The reduction of graphene oxide (GO) has been investigated for the mass production of graphene used in practical applications. Different reduction processes produce different properties in graphene, affecting the performance of the final materials or devices. Therefore, an understanding of the mechanisms of GO reduction is important for controlling the properties of functional two-dimensional systems. Here, we determined the average structure of reduced GO prepared via heating and photoexcitation and clearly distinguished their reduction mechanisms using ultrafast time-resolved electron diffraction, time-resolved infrared vibrational spectroscopy, and time-dependent density functional theory calculations. The oxygen atoms of epoxy groups are selectively removed from the basal plane of GO by photoexcitation (photon mode), in stark contrast to the behavior observed for the thermal reduction of hydroxyl and epoxy groups (thermal mode). The difference originates from the selective excitation of epoxy bonds via an electronic transition due to their antibonding character. This work will enable the preparation of the optimum GO for the intended applications and expands the application scope of two-dimensional systems.

    DOI: 10.1021/acsnano.9b03060

    Scopus

    PubMed

    researchmap

  • Unravelling the Effect of Pb Vacancy and Water Intercalated Defect on Structural and Electronic Properties in Methyl Ammonium Lead Iodide (MAPI) Perovskite via First Principles Calculations Reviewed

    M.A.A. Asad and K. Tsuruta

    MTC Letters   6   198 - 19   2019.6

     More details

    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)  

  • Rapid and reversible lithiation of doped biogenous iron oxide nanoparticles Reviewed

    Masaaki Misawa, Hideki Hashimoto, Rajiv Kalia, Syuji Matsumoto, Aiichiro Nakano, Fuyuki Shimojo, Jun Takada, Subodh Tiwari, Kenji Tsuruta, Priya Vashishta

    Scientific Reports   9 ( 1 )   1828 - 1828   2019.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41598-019-38540-8

    Scopus

    researchmap

  • First-principles Study on Water Dissociation in Grain Boundary of MAPbI<inf>3</inf> Perovskite Reviewed

    Asad, M.A.A., Sato, K., Tsuruta, K.

    MRS Advances   4 ( 36 )   2019

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.1557/adv.2019.329

    Scopus

    researchmap

  • Design and Assessment of Phononic Crystals for Controlling Ultrasonic Wave via Optical Measurement Method Reviewed

    Kensuke Manabe, Atsushi Ishikawa, Ken Yamamoto, Takefumi Kanda, Kenji Tsuruta

    IEEE International Ultrasonics Symposium, IUS   2018-October   2018.12

     More details

    Authorship:Corresponding author   Publishing type:Research paper (international conference proceedings)  

    Using an optical visualization technique, we experimentally measure ultrasonic propagation in phononic crystals consisting of a two-dimensional square array of copper wires in the water. Two different phononic crystals are designed and fabricated to exhibit waveguiding property and negative refraction of an ultrasonic wave at 200 kHz. The Fresnel diffraction method is employed to directly visualize intensity profile of the wavefront propagating in the phononic crystals, proving waveguiding and negative refraction of the ultrasonic wave. Non-invasive time-resolved imaging of an ultrasonic wave in artificial acoustic structures is thereby demonstrated, paving the way toward an efficient device design for an advanced ultrasonic wave control.

    DOI: 10.1109/ULTSYM.2018.8580129

    Scopus

    researchmap

  • Design of Non-Reciprocal Lamb Wave Filter by Heterojunction Phononic Crystals Reviewed

    Kenji Tsuruta, Shota Asada, Yuhei Iwasaki, Atsushi Ishikawa

    IEEE International Ultrasonics Symposium, IUS   2018-October   2018.12

     More details

    Authorship:Lead author, Corresponding author   Publishing type:Research paper (international conference proceedings)  

    We designed a new acoustic diode model, based on a one-dimensional structure consisting of piezoelectric ceramic films placed periodically in an epoxy plate. Specifically, the model is designed to exhibit non-reciprocal wave propagation in the audible and ultrasonic range. Our model includes no artificial forces to generate the asymmetry in the system but utilizes a mode-conversion mechanisms of elastic-wave propagation at interfaces. We demonstrate numerically that the model can achieve non-reciprocity at a particular frequency range for both S-mode and A-mode incidence of the Lamb wave. We further attempt to develop an additional model that can suppress unwanted backward propagation due to a large mismatch at the heterojunction interface.

    DOI: 10.1109/ULTSYM.2018.8579922

    Scopus

    researchmap

  • Transferable Analytical Model of Phononic Bandgap in Cross-Hole Phononic Crystals Reviewed

    Takahiro Nishino, Kenji Tsturuta, Atsushi Ishikawa

    2018 IEEE International Ultrasonics Symposium (IUS)   2018.10

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:{IEEE}  

    DOI: 10.1109/ultsym.2018.8579923

    researchmap

  • Numerical Simulation of Non-Reciprocal Acoustic Waveguide Based on Indirect Interband Transitions Reviewed

    Junyi Ge, Atsushi Ishikawa, Kenji Tsturuta

    2018 IEEE International Ultrasonics Symposium (IUS)   2018.10

     More details

    Authorship:Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:{IEEE}  

    DOI: 10.1109/ultsym.2018.8579977

    researchmap

  • Performance limit of daytime radiative cooling in warm humid environment Reviewed

    Takahiro Suichi, Atsushi Ishikawa, Yasuhiko Hayashi, Kenji Tsuruta

    AIP Advances   8 ( 5 )   2018.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Institute of Physics Inc.  

    Daytime radiative cooling potentially offers efficient passive cooling, but the performance is naturally limited by the environment, such as the ambient temperature and humidity. Here, we investigate the performance limit of daytime radiative cooling under warm and humid conditions in Okayama, Japan. A cooling device, consisting of alternating layers of SiO2 and poly(methyl methacrylate) on an Al mirror, is fabricated and characterized to demonstrate a high reflectance for sunlight and a selective thermal radiation in the mid-infrared region. In the temperature measurement under the sunlight irradiation, the device shows 3.4 °C cooler than a bare Al mirror, but 2.8 °C warmer than the ambient of 35 °C. The corresponding numerical analyses reveal that the atmospheric window in λ = 16 ∼ 25 μm is closed due to a high humidity, thereby limiting the net emission power of the device. Our study on the humidity influence on the cooling performance provides a general guide line of how one can achieve practical passive cooling in a warm humid environment.

    DOI: 10.1063/1.5030156

    Web of Science

    Scopus

    researchmap

  • Metaheuristic Ab Initio Optimum Search for Doping Effects in Nanocarbons Reviewed

    Tsuruta Kenji, Mitani Keiichi, Al Asad, Md. Abdullah, Nishina Yuta, Gotoh Kazuma, Ishikawa Atsushi

    THERMEC 2018: 10TH INTERNATIONAL CONFERENCE ON PROCESSING AND MANUFACTURING OF ADVANCED MATERIALS   941   2356 - 2359   2018

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    We have developed a combined approach of metaheuristic optimization algorithms (MOA), such as the genetic algorithm, with an ab-initio materials simulation engine. Concurrent run of the ab-initio calculations with each different parameter set selected by the MOA searches the optimum condition within a given input-parameter space. Using this methodology, the optimum dopant and its position/structure at a graphene edge are found to be a multiple N-atoms doping at graphitic sites, which predicts to lead to better charging/discharging performance when it is used as an anode material of Li-ion battery.

    DOI: 10.4028/www.scientific.net/MSF.941.2356

    Web of Science

    researchmap

  • Structure optimization of metallodielectric multilayer for high-efficiency daytime radiative cooling Reviewed

    Takahiro Suichi, Atsushi Ishikawa, Yasuhiko Hayashi, Kenji Tsuruta

    Proceedings of SPIE - The International Society for Optical Engineering   10369   2017

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE  

    Engineered metallodielectric nanostructures offer a new platform for controlling thermal emission in a desired manner, thus promise potential applications in passive cooling devices. Here, we present optimization design of metallodielectric multilayer structures for high-efficiency daytime radiative cooling and experimentally characterize their cooling performance. The device structure consists of alternating layers of SiO2 and PMMA on an Ag mirror, which works as a selective thermal emitter at 8-13 μm with a high reflectance for sunlight. Automated design scheme based on simulated annealing method combined with photonic-thermal analysis is developed and applied to search the optimized number and thickness of the layers. The evaluation function in the optimization process is predefined such that a net emission power would be maximized at the ambient temperature of 27 °C (300 K) under the sunlight irradiation of AM1.5G. The numerical results prove efficient radiative cooling to 3.0 °C lower than the ambient temperature, corresponding to 6.6 °C below the bare Ag mirror temperature. Based on the optimized design, the device is fabricated on an Al mirror by using reactive evaporation and spin-coating process over an area of 25 × 25 mm2. The reflectance and absorption properties of the fabricated device are characterized to demonstrate the selective thermal radiation through an atmospheric window. The equilibrium temperature of the device is also investigated to demonstrate the cooling performance under the direct sunlight irradiation.

    DOI: 10.1117/12.2273640

    Web of Science

    Scopus

    researchmap

  • Selective electroless plating of 3D-printed plastic structures for three-dimensional microwave metamaterials Reviewed

    Ishikawa, A., Kato, T., Takeyasu, N., Fujimori, K., Tsuruta, K.

    Applied Physics Letters   111 ( 18 )   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    A technique of selective electroless plating onto PLA-ABS (Polylactic Acid-Acrylonitrile Butadiene Styrene) composite structures fabricated by three-dimensional (3D) printing is demonstrated to construct 3D microwave metamaterials. The reducing activity of the PLA surface is selectively enhanced by the chemical modification involving Sn2+ in a simple wet process, thereby forming a highly conductive Ag-plated membrane only onto the PLA surface. The fabricated metamaterial composed of Ag-plated PLA and non-plated ABS parts is characterized experimentally and numerically to demonstrate the important bi-anisotropic microwave responses arising from the 3D nature of metallodielectric structures. Our approach based on a simple wet chemical process allows for the creation of highly complex 3D metal-insulator structures, thus paving the way toward the sophisticated microwave applications of the 3D printing technology. Published by AIP Publishing.

    DOI: 10.1063/1.4986203

    Web of Science

    Scopus

    researchmap

  • Automated Design of Infrared Digital Metamaterials by Genetic Algorithm Reviewed

    Yuya Sugino, Atsushi Ishikawa, Yasuhiko Hayashi, Kenji Tsuruta

    METAMATERIALS, METADEVICES, AND METASYSTEMS 2017   10343   2017

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE-INT SOC OPTICAL ENGINEERING  

    We demonstrate automatic design of infrared (IR) metamaterials using a genetic algorithm (GA) and experimentally characterize their IR properties. To implement the automated design scheme of the metamaterial structures, we adopt a digital metamaterial consisting of 7 x 7 Au nano-pixels with an area of 200 nm x 200 nm, and their placements are coded as binary genes in the GA optimization process. The GA combined with three-dimensional (3D) finite element method (FEM) simulation is developed and applied to automatically construct a digital metamaterial to exhibit pronounced plasmonic resonances at the target IR frequencies. Based on the numerical results, the metamaterials are fabricated on a Si substrate over an area of 1 mm x 1 mm by using an EB lithography, Cr/Au (2/20 nm) depositions, and liftoff process. In the FT-IR measurement, pronounced plasmonic responses of each metamaterial are clearly observed near the targeted frequencies, although the synthesized pixel arrangements of the metamaterials are seemingly random. The corresponding numerical simulations reveal the important resonant behavior of each pixel and their hybridized systems. Our approach is fully computer-aided without artificial manipulation, thus paving the way toward the novel device design for next-generation plasmonic device applications.

    DOI: 10.1117/12.2273607

    Web of Science

    researchmap

  • Design of non-reciprocal acoustic waveguides by indirect interband transitions Reviewed

    Ishikawa, A., Tsuruta, K.

    Japanese Journal of Applied Physics   56 ( 7 )   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We numerically demonstrate a non-reciprocal acoustic waveguide by utilizing the indirect interband transition between two guided modes. The waveguide, consisting of a water core sandwiched between parallel steel plates, is designed to support symmetric and asymmetric guided modes with different frequencies and wavevectors. Dynamic mode conversion is then achieved by applying spatio-temporal density modulation in the core of the waveguide to induce both frequency and wavevector shifts of the incident guided wave. Numerical simulations prove that the phase matching condition is satisfied only for the forward propagation, not for the backward one, thus realizing the non-reciprocal acoustic waveguide. Our approach based on a linear dynamic system may achieve wide-band tunable operation with a low-energy consumption, paving the way toward the sophisticated acoustic diode applications. (C) 2017 The Japan Society of Applied Physics.

    DOI: 10.7567/JJAP.56.07JB01

    Web of Science

    Scopus

    researchmap

  • Performance Improvement of HfS2 Transistors by Atomic Layer Deposition of HfO2 Reviewed

    Kanazawa, T., Amemiya, T., Upadhyaya, V., Ishikawa, A., Tsuruta, K., Tanaka, T., Miyamoto, Y.

    IEEE Transactions on Nanotechnology   16 ( 4 )   582 - 587   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    Hafnium disulfide (HfS2) is one of the transition metal dichalcogenides which is expected to have the high electron mobility and the finite bandgap. However, the fabrication process for HfS2 = based electron devices is not established, and it is required to bring out the superior transport properties of HfS2. In this report, we have investigated the effects of the atomic layer deposited HfO2 passivation on the current properties of HfS2 transistors. HfO2 passivation of the HfS2 surface enhanced the drain current and significantly reduced the hysteresis. Moreover, HfO2 passivation allows the use of a higher annealing temperature and further improvement of the drain current.

    DOI: 10.1109/TNANO.2017.2661403

    Web of Science

    Scopus

    researchmap

  • Cross-Polarized Surface-Enhanced Infrared Spectroscopy by Fano-Resonant Asymmetric Metamaterials Reviewed

    Ishikawa, A., Hara, S., Tanaka, T., Hayashi, Y., Tsuruta, K.

    Scientific Reports   7 ( 1 )   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:NATURE PUBLISHING GROUP  

    Plasmonic metamaterials have overcome fundamental limitations in conventional optics by their capability to engineer material resonances and dispersions at will, holding great promise for sensing applications. Recent demonstrations of metamaterial sensors, however, have mainly relied on their resonant nature for strong optical interactions with molecules, but few examples fully exploit their functionality to manipulate the polarization of light. Here, we present cross-polarized surface-enhanced infrared absorption (SEIRA) by the Fano-resonant asymmetric metamaterial allowing for strong background suppression as well as significant field enhancement. The metamaterial is designed to exhibit the controlled Fano resonance with the cross-polarization conversion property at 1730 cm(-1), which spectrally overlaps with the C=O vibrational mode. In the cross-polarized SEIRA measurement, the C=O mode of poly(methyl methacrylate) molecules is clearly observed as a distinct dip within a Fano-resonant transmission peak of the metamaterial. The vibrational signal contrast is then improved based on the cross-polarized detection scheme where only the light interacting with the metamaterial-molecular coupled system is detected by totally eliminating the unwanted background light. Our metamaterial approach achieves the zeptomole sensitivity with a large signal-to-noise ratio in the far-field measurement, paving the way toward the realization of ultrasensitive IR inspection technologies.

    DOI: 10.1038/s41598-017-03545-8

    Web of Science

    Scopus

    researchmap

  • Robust plasmonic hot-spots in a metamaterial lattice for enhanced sensitivity of infrared molecular detection Reviewed

    Ishikawa, A., Hara, S., Tanaka, T., Zhang, X., Tsuruta, K.

    Applied Physics Letters   111 ( 24 )   2017

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    High-density and long-lived plasmonic hot-spots are an ideal system for high-sensitive surface-enhanced infrared absorption (SEIRA), but these conditions arc usually incompatible due to unwanted near-field coupling between the adjacent unit structures. Here, by fully controlling plasmonic interference in a metamaterial lattice, we experimentally demonstrate densely packed long-lived quadrupole plasmons for high-sensitive SEIRA. The metamaterial consists of a strongly coupled array of super-and sub-radiant plasmonic elements to exhibit an electromagnetic transparency mode at 1730 cm(-1), which spectrally overlaps with the C=O vibrational mode. In the SEIRA measurement, the C=O mode of poly(methyl methacrylate) molecules is clearly observed as a distinct dip within a transmission peak of the metamaterial. The corresponding numerical simulations reveal that constructive interference uniformly forms coherent quadrupole plasmons over the metamaterial lattice, leading to a stronger molecular signal from the system. Our metamaterial approach provides a robust way to construct ideal hot-spots over the sample, paving the way toward a reliable sensing platform of advanced infrared inspection technologies. Published by AIP Publishing.

    DOI: 10.1063/1.5004703

    Web of Science

    Scopus

    researchmap

  • Rectification of Lamb wave propagation in thin plates with piezo-dielectric periodic structures Reviewed

    Iwasaki, Y., Tsuruta, K., Ishikawa, A.

    Japanese Journal of Applied Physics   55 ( 7 )   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Based on a heterostructured plate consisting of piezoelectric-ceramic/epoxy-resin composites with different periodicities, we design a novel acoustic diode for the symmetrical/asymmetrical (S/A) mode of Lamb wave at audible ranges. The acoustic diode is constructed with two parts, i.e., the mode conversion part and the mode selection part, and the mode conversion mechanism at the interface is applied to the mode hybridization from S to S+A and for the mode conversion from A to S. The phonon band structures for each part are calculated and optimized so that the mode selection is realized for a specific mode at the junction. Finite-element simulations prove that the proposed acoustic diode achieves efficient rectification at audio frequency ranges for both S and A mode incidences of the Lamb wave. (C) 2016 The Japan Society of Applied Physics

    DOI: 10.7567/JJAP.55.07KB02

    Web of Science

    Scopus

    researchmap

  • Controlled Fano Resonances via Symmetry Breaking in Metamaterials for High-Sensitive Infrared Spectroscopy Reviewed

    Shuhei Hara, Atsushi Ishikawa, Takuo Tanaka, Yasuhiko Hayashi, Kenji Tsuruta

    METAMATERIALS, METADEVICES, AND METASYSTEMS 2016   9918   2016

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE-INT SOC OPTICAL ENGINEERING  

    A high-sensitive polarized surface-enhanced infrared absorption (polarized SEIRA) is proposed and demonstrated by utilizing the resonant coupling of Fano-resonant mode of the asymmetric metamaterials and IR vibrational mode of a polymer nano-film. The asymmetric metamaterials consisting of an Au nano-rod pair with a coupling nano-antenna were fabricated and characterized to demonstrate the controlled Fano resonances at 1730 cm(-1), which spectrally overlapped with the C=O stretching vibrational mode. In the co-polarized SEIRA measurement, the C=O mode of the PMMA nano-film was clearly observed as a conventional anti-resonant peak within the Fano line-shape of the metamaterial. For the cross-polarized case, on the other hand, a distinctive dip appeared within a cross-polarized transmission peak of the metamaterial. Since the unwanted background is strongly suppressed in the cross-polarized detection scheme, the signal contrast was dramatically improved, allowing for the attomole detection of the C=O bond in the far-field measurement. Our metamaterial approach achieves the significant improvement of signal-to-background ratio in the far-field measurement, thus paving the way toward the high-sensitive analysis of functional group in direct IR spectroscopy.

    DOI: 10.1117/12.2237559

    Web of Science

    researchmap

  • Doping effect on photoabsorption and charge-separation dynamics in light-harvesting organic molecule Reviewed

    Ohmura, Satoshi, Tsuruta, Kenji, Shimojo, Fuyuki, Nakano, Aiichiro

    Aip Advances   6 ( 1 )   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    Using ab-initio theoretical methods, we demonstrate possible enhancement of photo-conversion efficiency of an organic solar cell via intentional doping in molecular graphene-fullerene heterojunction [the hexabenzocoronene (HBC)-triethylene glycol (TEG)-C-60 molecule]. Photoabsorption analysis indicates oxygen substitution into HBC leads to an extension of the spectra up to an infrared regime. A quantum-mechanical molecular dynamics simulation incorporating nonadiabatic electronic transitions reveals that a dissociated charge state (D+ and A(-)) in the O-doped system is more stable than the pristine case due to the presence of an effective barrier by the TEG HOMO/LUMO level. We also find that oxygen doping in HBC enhances the intermolecular carrier mobility after charge separation. On the other hand, the pristine molecule undergoes rapid recombination between donor and acceptor charges at the interface. These analyses suggest that the graphene oxidation opens a new window in the application of organic super-molecules to solar cells. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

    DOI: 10.1063/1.4939848

    Web of Science

    researchmap

  • Few-layer HfS2 transistors Reviewed

    Kanazawa, Toru, Amemiya, Tomohiro, Ishikawa, Atsushi, Upadhyaya, Vikrant, Tsuruta, Kenji, Tanaka, Takuo, Miyamoto, Yasuyuki

    Scientific Reports   6   2016

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:NATURE PUBLISHING GROUP  

    HfS2 is the novel transition metal dichalcogenide, which has not been experimentally investigated as the material for electron devices. As per the theoretical calculations, HfS2 has the potential for well-balanced mobility (1,800 cm(2)/V.s) and bandgap (1.2 eV) and hence it can be a good candidate for realizing low-power devices. In this paper, the fundamental properties of few-layer HfS2 flakes were experimentally evaluated. Micromechanical exfoliation using scotch tape extracted atomically thin HfS2 flakes with varying colour contrasts associated with the number of layers and resonant Raman peaks. We demonstrated the I-V characteristics of the back-gated few-layer (3.8 nm) HfS2 transistor with the robust current saturation. The on/off ratio was more than 10(4) and the maximum drain current of 0.2 mu A/mu m was observed. Moreover, using the electric double-layer gate structure with LiClO4: PEO electrolyte, the drain current of the HfS2 transistor significantly increased to 0.75 mA/mu m and the mobility was estimated to be 45 cm(2)/V.s at least. This improved current seemed to indicate superior intrinsic properties of HfS2. These results provides the basic information for the experimental researches of electron devices based on HfS2.

    DOI: 10.1038/srep22277

    Web of Science

    researchmap

  • Effect of the HfO2 passivation on HfS2 Transistors Reviewed

    T. Kanazawa, T. Amemiya, V. Upadhyaya, A. Ishikawa, K. Tsuruta, T. Tanaka, Y. Miyamoto

    2016 IEEE 16TH INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY (IEEE-NANO)   865 - 867   2016

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    Hafnium Disulfide (HfS2) is one of the transition metal dichalcogenides which is expected to have high electron mobility and finite bandgap. However, the fabrication process for HfS2 based electron devices has not been established, and it is required to bring out the superior transport properties of HfS2. In this report, we have investigated the effects of ALD HfO2 passivation on the current properties of HfS2 Transistors. HfO2 passivation of HfS2 surface achieved the improvement in drain current and significant reduction of hysteresis. The charge trapping at the outermost surface seems to be the dominant factor for degradation of the current stability.

    Web of Science

    researchmap

  • First-principles calculation of amorphization of Si and P co-doped α-Fe2O3

    Mitani K., Tsuruta K., Ishikawa A.

    Meeting Abstracts of the Physical Society of Japan   71   1504 - 1504   2016

     More details

    Language:Japanese   Publisher:The Physical Society of Japan  

    DOI: 10.11316/jpsgaiyo.71.2.0_1504

    CiNii Article

    researchmap

  • Terahertz wavefront control by tunable metasurface made of graphene ribbons Reviewed

    Takumi Yatooshi, Atsushi Ishikawa, Kenji Tsuruta

    APPLIED PHYSICS LETTERS   107 ( 5 )   2015.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    We propose a tunable metasurface consisting of an array of graphene ribbons on a silver mirror with a SiO2 gap layer to control reflected wavefront at terahertz frequencies. The graphene ribbons exhibit localized plasmon resonances depending on their Fermi levels to introduce abrupt phase shifts along the metasurface. With interference of the Fabry-Perot resonances in the SiO2 layer, phase shift through the system is largely accumulated, covering the 0-to-2 pi range for full control of the wavefront. Numerical simulations prove that wide-angle beam steering up to 53 degrees with a high reflection efficiency of 60% is achieved at 5 THz within a switching time shorter than 0.6 ps. (C) 2015 AIP Publishing LLC.

    DOI: 10.1063/1.4927824

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Terahertz acoustic wave on piezoelectric semiconductor film via large-scale molecular dynamics simulation Reviewed

    Ryo Hikata, Kenji Tsuruta, Atsushi Ishikawa, Kazuhiro Fujimori

    JAPANESE JOURNAL OF APPLIED PHYSICS   54 ( 7 )   2015.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    By atomistic simulation, we investigate an acoustic wave at THz frequencies in nanoscale thin films of aluminum-nitride piezoelectric material. A mode analysis reveals that the thickness longitudinal mode along the [0001] direction exists stably at the atomic level. To control the acoustic wave, we introduce a phononic crystal (PC) structure in the films. We determine the band-gap frequency in the phonon dispersion of the PC structure and confirm via molecular dynamics simulation that the acoustic wave within the band-gap frequency can be confined by a waveguide structure with a PC. The possibility of designing and controlling a THz acoustic wave in a nanoscale thin film with a PC is thereby demonstrated. (C) 2015 The Japan Society of Applied Physics

    DOI: 10.7567/JJAP.54.07HB07

    Web of Science

    researchmap

  • Fabrication of Thin-Film HfS2 FET Reviewed

    T. Kanazawa, T. Amemiya, A. Ishikawa, V. Upadhyaya, K. Tsuruta, T. Tanaka, Y. Miyamoto

    2015 73RD ANNUAL DEVICE RESEARCH CONFERENCE (DRC)   2015-August   217 - 218   2015

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    DOI: 10.1109/DRC.2015.7175643

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Terahertz wavefront control by graphene metasurface Reviewed

    Takumi Yatooshi, Atsushi Ishikawa, Kenji Tsuruta

    Materials Research Society Symposium Proceedings   1788   37 - 42   2015

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Materials Research Society  

    We propose and numerically investigate a tunable metasurface made of an array of graphene ribbons to dynamically control terahertz (THz) wavefront. The metasurface consists of graphene micro ribbons on a silver mirror with a SiO2 gap layer. The graphene ribbons are designed to exhibit localized plasmon resonances depending on their Fermi levels to introduce abrupt phase shifts along the metasurface. With interference of the Fabry-Perot resonances in the SiO2 layer, phase shift through the system is largely accumulated, covering up to 2jt range for full control of the THz wavefront. Numerical simulations prove that wide-angle reflected THz beam steering from -53° to +53° with a high reflection efficiency as high as 60% is achieved at 5 THz while the propagation direction of THz beam could be switched within 0.6 ps.

    DOI: 10.1557/opl.2015.730

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • A density functional study of vacancy formation in grain boundaries of undoped alpha-alumina Reviewed

    Takafumi Ogawa, Akihide Kuwabara, Craig A. J. Fisher, Hiroki Moriwake, Katsuyuki Matsunaga, Kenji Tsuruta, Satoshi Kitaoka

    ACTA MATERIALIA   69   365 - 371   2014.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Recent oxygen permeation experiments with cc-alumina have shown that the two major diffusing species at the grain boundaries, i.e. oxygen and aluminum vacancies, switch over in terms of their dominance depending on the oxygen partial pressure at high temperatures (the so-called p-n transition). In order to investigate this transition behavior the formation energies of charged oxygen and aluminum vacancies at Al2O3 grain boundaries were evaluated using density functional theory. The electronic structures affecting the carrier concentrations are assessed for three types of grain boundaries. The ratios of the grain boundary band gaps relative to the bulk value lie in the range of 0.6-0.85 depending on the degree of grain boundary misorientation. From the formation energies we find that, at band gaps around 60% compared to the bulk value, the dominant vacancy alters depending on the pressure, consistent with the oxygen permeation experiments. Our results suggest that the band bap narrowing occurring at grain boundaries enhances the creation of oxygen vacancies and conduction electrons, facilitating the observed transition. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.actamat.2014.01.059

    Web of Science

    researchmap

  • Core structure and dissociation energetics of basal edge dislocation in alpha-Al2O3: A combined atomistic simulation and transmission electron microscopy analysis Reviewed

    Kenji Tsuruta, Eita Tochigi, Yuki Kezuka, Kazuaki Takata, Naoya Shibata, Atsutomo Nakamura, Yuichi Ikuhara

    ACTA MATERIALIA   65   76 - 84   2014.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    Using large-scale molecular dynamics (MD) simulations, we investigate the energetics and local structures/stresses of partial dislocations, 1/3 &lt; 01 (1) over bar0 &gt; and 1/3 &lt; 10 (1) over bar0 &gt;, dissociated from the 1/3 &lt; 11 (2) over bar0 &gt; perfect basal edge dislocation in alpha-Al2O3. The validity of the model adopted in the simulation is confirmed by comparing with theoretical stress/strain distributions and with those experimentally obtained from a high-resolution transmission electron microscopy (HRTEM) observation. Partial dislocation pairs have a stable inter-core distance (similar to 2 nm), which is also a phenomenon that is observed in the HRTEM experiments. The distance between the partials can be explained quantitatively by the balance between an elastic core core repulsion and an effective attractive force against the extension of stacking faults (SFs). A comparison is made for two types of core structures of partial dislocations: a pair of partials with Al-terminated/O-terminated extra-half planes and that with Al-/Al-terminated ones. The overall tendency of the inter-core interaction and the equilibrium distances are the same in both cases, whereas the Al-O-terminated pair is slightly favourable in energy at the equilibrium distance. A residual shear stress on the SF plane is observed in the MD results, which can be attributed to local atomic structure in the SF. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.actamat.2013.11.035

    Web of Science

    researchmap

  • Phononic-Crystal Acoustic Lens by Design for Energy-Transmission Devices Reviewed

    Yusuke Kanno, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    ELECTRONICS AND COMMUNICATIONS IN JAPAN   97 ( 1 )   22 - 27   2014.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-BLACKWELL  

    The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal/ceramic cylinders placed periodically in water. The lens effect is observed for the far-field wave in phononic crystals with two-layered and graded-index structure. We compare the focal intensity and the energy transmission efficiency in these numerical experiments, and show that a novel energy-transmission device can be designed using phononic crystals. (c) 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 97(1): 22-27, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11491

    DOI: 10.1002/ecj.11491

    Web of Science

    researchmap

  • Graphene metasurface for THz wavefront control Reviewed

    Yatooshi T, Ishikawa A, Tsuruta K

    JSAP-OSA Joint Symposia, JSAP 2014   2014

  • Effect on acoustic wave propagation by the interior structure of waveguide filled up with water

    Tsubouchi Kazuya, Tadokoro Masaaki, Fujimori Kazuhiro, Ishikawa Atsushi, Tsuruta Kenji, Fukano Hideki

    The Proceedings of The Computational Mechanics Conference   2014.27   325 - 326   2014

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    DOI: 10.1299/jsmecmd.2014.27.325

    CiNii Article

    researchmap

  • Optically Powered Voltage Supply Device for Effective Utilization of Optical Energy in the Fiber-to-the-Home Network Reviewed

    Hideki Fukano, Takeshi Shinagawa, Kenji Tsuruta

    ELECTRONICS AND COMMUNICATIONS IN JAPAN   96 ( 10 )   37 - 42   2013.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-BLACKWELL  

    SUMMARYAn optically powered device using an InGaAs photodiode has been developed. This study aims to harvest light energy (2.8 to 500 mu W) from the FTTH (fiber-to-the-Home) network and to utilize it for operating remote sensors without an external energy source. We designed the booster circuit and evaluated its characteristics, confirming that it could boost an input voltage of 0.3 V to 3.0 V. We also evaluated the characteristics of an InGaAs photodiode and confirmed that it could output a voltage over 0.3 V using 10-mu W input light. We demonstrate that a ready-made sensor can be operated with an input optical power as low as 10 mu W. (c) 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(10): 37-42, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11472

    DOI: 10.1002/ecj.11472

    Web of Science

    researchmap

  • Design and development of highly ecient transducer for ultrasonic wireless power transmission system Reviewed

    Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    ELECTRICAL ENGINEERING IN JAPAN   184 ( 3 )   27 - 35   2013.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY-BLACKWELL  

    In this paper, a transducer that is suitable for the ultrasonic wireless power transmission system is discussed. The transducer is designed based on Mason's equivalent circuit theory, basically. The transducer was developed using design parameters optimized by multiphysics analysis. As a result, it is confirmed that the transmission eciency is drastically improved to more than 50%. This result suggests that wireless power transmission by acoustic wave is feasible. (c) 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 2735, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22406

    DOI: 10.1002/eej.22406

    Web of Science

    researchmap

  • Interaction between Atomic Vacancies in Crystalline Si Wafer: A Tight-binding Molecular Dynamics Study Reviewed

    K. Takata, K. Tsuruta, T. Ogawa, H. Iyetomi

    Trans. Meter. Res. Soc. J   37 ( 2 )   143 - 146   2012.4

     More details

    Language:English   Publisher:The Materials Research Society of Japan  

    Vacancy interaction in crystalline Si wafer is studied by numerical simulation based on the Tight-Binding Molecular Dynamics (TBMD) method. We evaluate an effective interaction between vacancy pair in bulk and in a thin slab as model systems of a Si wafer. In the case of vacancy pair in bulk crystal, results reveal that there is an effective "capture radius" of the vacancies to form a divacancy at around 8Å at 300K and 13Å at 600K. Surface structure involving vacancies in Si slab undergoes a reconstruction accompanying dimer-rows in [110] direction initiated by the vacancies. The capture radius is also found to exist in the slab and binding energy of the divacancy has depth dependence due to the surface effect.

    DOI: 10.14723/tmrsj.37.143

    CiNii Article

    researchmap

  • Experimental Analysis of Optical Fiber Multimode Interference Structure and its Application to Refractive Index Measurement Reviewed

    Shuji Taue, Yoshiki Matsumoto, Hideki Fukano, Kenji Tsuruta

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 4 )   2012.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We investigated a fiber-based multimode interference phenomenon in the wavelength domain by using a white light source and an optical spectrum analyzer. This phenomenon was produced by a larger-core optical fiber joined at both ends with smaller-core optical fibers. We examined the variation of interference wavelength with changes in the length of the larger-core fiber. The interference wavelengths were blue-shifted and the interference signals were sharpened with an increase in the length of the larger-core fiber. The calculated results agreed well with the measured results. Next, we investigated how the input and output fibers with a small core influence the interference signal characteristics. By comparing the amplitude differences of the interference signal we find the conditions of input and output (I/O) fibers for higher sensitivity. In addition, an interference-signal shift was observed by changing the medium surrounding an multimode interference (MMI) structure. The amount of shift increased at a longer wavelength. This leads to the sensitive detection of the refractive index. Finally, a demonstration of the optical fiber refractometer with a multimode interference structure was given by refractive-index measurements of ethanol/water solutions. (C) 2012 The Japan Society of Applied Physics

    DOI: 10.1143/JJAP.51.04DG14

    Web of Science

    researchmap

  • An investigation for optimum design of matching circuit in highly efficient RF-DC conversion circuit by genetic algorithm Reviewed

    Kondo Y, Fujimori K, Tsuruta K

    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)   194 - 197   2012

  • Characteristics of RF-DC conversion circuit for wireless power transmission using the low resistance GaN schottky barrier diode Reviewed

    Fujimori K, Wagi T, Tsuruta K, Nogi S, Ozawa Y, Furukawa M, Fujiwara T

    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)   190 - 193   2012

  • Design and development of highly efficient transducer for ultrasonic wireless power transmission system Reviewed

    Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    IEEJ Transactions on Electronics, Information and Systems   132 ( 3 )   1 - 343   2012

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Institute of Electrical Engineers of Japan  

    In this paper, the transducer that is suitable for the ultrasonic wireless power transmission system is discussed. The transducer is designed based on the Mason's equivalent circuit theory, basically. Design parameters of the transducer are optimized for by using the multi physics analysis and developed. As results, it is confirmed that the transmission efficiency is drastically improved to more than 50%. This result suggests that the WPT by acoustic wave is practicable. © 2012 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.132.337

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Frequency characteristic of transmission efficiency depended on matching condition of transducer in ultrasonic wireless power transmission system Reviewed

    Fujimori K, Tominaga S, Tanda K, Tsuruta K, Nogi S

    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)   166 - 169   2012

  • An ab initio analysis of electronic states associated with a silicon vacancy in cubic symmetry Reviewed

    OGAWA Takafumi, TSURUTA Kenji, IYETOMI Hiroshi

    Solid State Communications   151 ( 21 )   1605 - 1608   2011.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.ssc.2011.07.020

    Web of Science

    Scopus

    researchmap

  • Negative Refraction and Energy-Transmission Efficiency of Acoustic Waves in Two-Dimensional Phononic Crystal: Numerical and Experimental Study Reviewed

    Yuuki Kasai, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    JAPANESE JOURNAL OF APPLIED PHYSICS   50 ( 6 )   2011.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN SOC APPLIED PHYSICS  

    The negative refraction of acoustic waves in a two-dimensional phononic-crystal slab is studied by numerical simulation based on the finite-difference time-domain (FDTD) method and by ultrasonic measurement. The incident-angle dependences of energy-transmission efficiency in the simulation and experiment are in good agreement in the frequency range of approximately 1.2 MHz. Using the FDTD method, we optimize the efficiency by varying structural parameters such as filling fraction and slab thickness. The effect of deviation from the ideal crystallinity is also evaluated quantitatively via the simulation. These results indicate that an energetically efficient acoustic lens can be fabricated by carefully optimizing the structure of the phononic crystal. (C) 2011 The Japan Society of Applied Physics

    DOI: 10.1143/JJAP.50.067301

    Web of Science

    researchmap

  • Structures and Local Electronic States of Dislocation Loop in 4H-SiC via a Linear-Scaling Tight-Binding Study Reviewed

    Fusanori Hamasaki, Kenji Tsuruta

    MATERIALS TRANSACTIONS   52 ( 4 )   672 - 676   2011.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    The atomic- and electronic-level structures of a dislocation loop and a stacking fault in 4H-SiC crystal are investigated by using large-scale tight-binding (TB) molecular-dynamics simulation. We employ a linear-scaling TB method implemented on a parallel computer in order to accelerate the 9,600-atoms calculation which is required for such a nanoscale simulation. We find that the initial configuration that involves unstable C-C networks around the dislocation loop is relaxed to a structure having six-membered rings, and that the distribution of electron populations is inhomogeneous on the loop. The local electronic density of states shows two peaks in the bulk band gap, where one of these peaks may correspond to the defect state observed in EBIC and CL experiments. [doi:10.2320/matertrans.MBW201024]

    DOI: 10.2320/matertrans.MBW201024

    Web of Science

    researchmap

  • Design of Anti-Resonance Transducer and Its Abilities for Efficient Ultrasonic Wireless Power Transmission System Reviewed

    Yuki Hori, Yusuke Shigeta, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    2011 41ST EUROPEAN MICROWAVE CONFERENCE   67 - 70   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    We developed a fundamental testbed and investigated the suitable transducer for the wireless power transmission (WPT). We also had reported experimental results of the transmission efficiency in water by using the commercial transducer (COM) which only designed to match to the acoustic impedance of water by its structure and the electric impedance of the transmitter and receiver by matching networks. In this paper, we investigate the transducer (DEV) for improving the transmission efficiency based on the Mason's equivalent circuit. For deciding a structure and materials of the transducer, we used ANSYS well-known as the multi-physics simulator.
    In this result, it is confirmed that the transmission efficiency is drastically improved from less than 1% to 60% compared to our previous report. In addition, we manufactured designed transducer, and confirmed the system's efficiency is about 50 % experimentally. This result also suggests that WPT by the acoustic wave be practicable.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • The Influences of Diode Parameters on Conversion Efficiency of RF-DC Conversion Circuit for Wireless Power Transmission System Reviewed

    Kazuhiro Fujimori, Sho-ichi Tamaru, Kenji Tsuruta, Shigeji Nogi

    2011 41ST EUROPEAN MICROWAVE CONFERENCE   57 - 60   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    RF-DC conversion circuit is one of the most important components in the wireless power transmission technologies. For realizing highly efficient wireless power transmission, it is necessary to design the RF-DC conversion circuit with high conversion efficiency, and the designing method of the circuit is actively studied. In this paper, the influences of diode parameters, such as its resistance, junction capacitance, parasitic reactance, and so on, on the conversion efficiency of the RF-DC conversion circuit are investigated to clarify the characteristic of the diode for obtaining highly efficient RF-DC conversion circuit.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Development of highly efficient transducer for wireless power transmission system by ultrasonic Reviewed

    Yusuke Shigeta, Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings   171 - 174   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    We developed a fundamental testbed and investigated the suitable transducer for the wireless power transmission (WPT). We also reported experimental results of the transmission efficiency in water by using the commercial transducer (COM) which only designed to match to the acoustic impedance of water and the electric impedance of the transmitter and receiver. In this paper, we investigate the transducer for improving the efficiency based on the Mason's equivalent circuit. For deciding a structure and materials of the transducer, we used ANSYS well-known as the multi-physics simulator. In this result, it is confirmed that the transmission efficiency is drastically improved from less than 1% to 60%. In addition, we made designed transducer, and confirmed the systems' efficiency is about 50 %. This result suggests that the WPT by acoustic wave is practicable. © 2011 IEEE.

    DOI: 10.1109/IMWS.2011.5877115

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Initial Stage of Consolidation of Silicon-Carbide Nanocrystals under Pressure: A Tight-Binding Molecular-Dynamics Study Reviewed

    Kenji Tsuruta

    JOURNAL OF NANOMATERIALS   2011

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:HINDAWI PUBLISHING CORPORATION  

    Tight-binding molecular-dynamics (TBMDs) simulations are performed to study atomic and electronic structures during high-temperature consolidation processes of nanocrystalline silicon carbide under external pressure. We employ a linear-scaling method (the Fermi-operator expansion method) with a scalable parallel algorithm for efficient calculations of the long time-scale phenomena. The results show that microscopic processes of the consolidation depend strongly on initial orientations of the nanocrystals. It is observed that an orientational rearrangement of the nanocrystals initially misaligned is induced by an instantaneous shearing force between nanocrystals, whereas the aligned system undergoes densification without shearing. Analysis on an effective-charge distribution and an average bond-order distribution reveals electronic-structure evolutions during these processes.

    DOI: 10.1155/2011/308495

    Web of Science

    researchmap

  • Molecular Dynamics Study on Dielectric Properties of Silicon Oxynitride: Composition and Microstructure Dependence Reviewed

    Munemasa Tomita, Kenji Tsuruta

    ELECTROCERAMICS IN JAPAN XIV   485   287 - 290   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:TRANS TECH PUBLICATIONS LTD  

    Extra-long molecular-dynamics simulations are performed to study the interplay between dielectric properties and microstructures of silicon oxynitride. We quantitatively obtained the ionic permittivity and its linear dependence on nitrogen concentration. Analyses on microstructure of the oxynitride show that, as the N concentration increases, N atoms enter Si-O networks creating smaller-sized rings. While overall tendency of dielectric constant is monotonic increase on the N concentration, microscopic characteristics, such as local displacement of atoms, are strongly depend on local bonding environments.

    DOI: 10.4028/www.scientific.net/KEM.485.287

    Web of Science

    researchmap

  • Acoustic lens using sonic crystal for energy-transmission application Reviewed

    Y. Kanno, Y. Kasai, K. Tsuruta, K. Fujimori, H. Fukano, S. Nogi

    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings   207 - 210   2011

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)  

    We design and characterize a two-dimensional sonic crystal (SC) to manipulate the propagation of acoustic waves by numerical simulation based on the finite-difference time-domain (FDTD) method and by ultrasonic measurement. Two types of SC for an acoustic lens effect are studied. One is a homogeneous periodic structure exhibiting negative refraction, and the other has a hetero-structure. Negative refraction behavior in the simulation is good agreement with the experiment in the frequency range around 1.2MHz. We also observe a lens effect for far-field wave in the hetero-structured SC. These results indicate that a novel energy-transmission/harvesting device can be designed using SCs. © 2011 IEEE.

    DOI: 10.1109/IMWS.2011.5877131

    Scopus

    researchmap

  • Density-Functional Analysis on Vacancy Orbital and its Elastic Response of Silicon Reviewed

    Takafumi Ogawa, Kenji Tsuruta, Hiroshi Iyetomi, Hiroshi Y. Kaneta, Terutaka Goto

    RELIABILITY AND MATERIALS ISSUES OF SEMICONDUCTOR OPTICAL AND ELECTRICAL DEVICES AND MATERIALS   1195   2010

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOC  

    Recent experiments on ultrasonic measurements of non-doped and boron-doped silicon indicate that vacancies in crystalline silicon can be detected through the elastic softening at low temperature. This is attributed to enhanced response of electronic quadrupole localized at the vacancies to the elastic strain. In the present work, the electronic quadrupole moment of the vacancy orbital in silicon and their strain susceptibility are evaluated quantitatively by using the density-functional method. We show the orbital of gap state is localized around vacancy but extended over several neighbors. The effect of applied magnetic field on the vacancy orbital and its multipole structures are also investigated. We find that the results obtained from these calculations are consistent with the ultrasonic experiments.

    DOI: 10.1557/PROC-1195-B08-11

    Web of Science

    researchmap

  • Classical and Hybrid Density-Functional/Classical Molecular Dynamics Study of Dislocation Core in Alumina Ceramic Reviewed

    Kenji Tsuruta, Toshiyuki Koyama, Shuji Ogata

    MATERIALS TRANSACTIONS   50 ( 5 )   1015 - 1018   2009.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    We perform molecular-dynamics simulation,, to investigate the atomic and electronic structures of a basal edge dislocation it) alpha-Al2O3. The core structure consisting of two non-stoichiometric partial dislocations, which has been recently proposed by an experiment, is examined by an empirical interatomic-potential model and by a hybrid quantum/classical approach. The atomic rearrangements in the full and in the partial dislocation cores are analyzed. The local electronic structure in the full dislocation core is evaluated by the density-functional method applied for a quantum-cluster region in the hybrid simulations. Interaction potentials between partial dislocations are investigated by the classical model. Results preliminarily obtained show that the partials aligned normal to a basal plane ({10001}) has a short-ranged repulsive nature approximately within 8 angstrom. [doi: 10.2320/matertrans.MC200833]

    DOI: 10.2320/matertrans.MC200833

    Web of Science

    researchmap

  • An FDTD Analysis of Nanostructured Electromagnetic Metamaterials Using Parallel Computer Reviewed

    Ryosuke Umeda, Chieko Totsuji, Kenji Tsuruta, Hiroo Totsuji

    MATERIALS TRANSACTIONS   50 ( 5 )   994 - 998   2009.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Metamaterial with negative permittivity and permeability is studied by means of computer simulations. We analyze the electromagnetic response of nanostructured metamaterials to evanescent waves at optical frequency via the finite-difference time-domain simulations on parallel computer. Effects of the nanostructure on dielectric and magnetic properties are taken into account by introducing the Drude-Lorentz model in the materials dispersion. Size effect on the dispersion is examined by comparing the model with that of a noble metal particle. A re-focusing and an amplification of the evanescent waves propagating through a metamaterial, consisting of metal slabs/vacuum stacking, are demonstrated for the frequency range at 614-744 THz. By properly treating the materials dispersion, we show that the nanostructured metamaterial may behave as a left-handed material in the optical range. [doi:10.2320/matertrans.MC200822]

    DOI: 10.2320/matertrans.MC200822

    Web of Science

    researchmap

  • Negative Refraction of Acoustic Waves in a Two-Dimensional Phononic Crystal via FDTD Simulation Reviewed

    Tomoyuki Kurose, Kenji Tsuruta, Chieko Totsuji, Hiroo Totsuji

    MATERIALS TRANSACTIONS   50 ( 5 )   1004 - 1007   2009.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Negative refraction of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in a liquid. By comparing several combinations of materials for metal cylinder and liquid, we analyze the dependence of the band structures on sound speed and density of liquid media. The negative refraction of the acoustic waves is observed at the interfaces between the phononic crystal slab and the liquid. We find that an acoustic "lens effect" with the slab appears due to the negative refractions. The relationship between the focal intensity in the lens effect and the band structure of the phononic crystal is quantitatively discussed. [doi: 10.2320/matertrans.MC200823]

    DOI: 10.2320/matertrans.MC200823

    Web of Science

    researchmap

  • A classical-map simulation of two-dimensional electron fluid: an extension of classical-map hypernetted-chain theory beyond the hypernetted-chain approximation Reviewed

    Chieko Totsuji, Takashi Miyake, Kenta Nakanishi, Kenji Tsuruta, Hiroo Totsuji

    JOURNAL OF PHYSICS-CONDENSED MATTER   21 ( 4 )   2009.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    A method for numerically simulating quantum systems is proposed and applied to the two-dimensional electron fluid at T = 0. This method maps quantum systems onto classical ones in the spirit of the classical-map hypernetted-chain theory and performs simulations on the latter. The results of the simulations are free from the assumption of the hypernetted-chain approximation and the neglect of the bridge diagrams. A merit of this method is the applicability to systems with geometrical complexity and finite sizes including the cases at finite temperatures. Monte Carlo and molecular dynamics simulations are performed corresponding to two previous proposals for the &apos;quantum&apos; temperature and an improvement in the description of the diffraction effect. It is shown that one of these two proposals with the improved diffraction effect gives significantly better agreement with quantum Monte Carlo results reported previously for the range of 5 &lt;= r(s) &lt;= 40. These results may serve as the basis for the application of this method to finite non-periodic systems like quantum dots and systems at finite temperatures.

    DOI: 10.1088/0953-8984/21/4/045502

    Web of Science

    researchmap

  • Spin polarization of two-dimensional electron system in parabolic potential Reviewed

    Takashi Miyake, Chieko Totsuji, Kenta Nakanishi, Kenji Tsuruta, Hiroo Totsuji

    PHYSICS LETTERS A   372 ( 40 )   6197 - 6201   2008.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    We analyze the ground state of the two-dimensional quantum system of electrons confined in a parabolic potential with the system size around 100 at 0 K. We map the system onto a classical system on the basis of the classical-map hypernetted-chain (CHNC) method which has been proven to work in the integral-equation-based analyses of uniform systems and apply classical Monte Carlo and molecular dynamics simulations. We find that, when we decrease the strength of confinement keeping the number of confined electrons fixed, the energy of the spin-polarized state with somewhat lower average density becomes smaller than that of the spin-unpolarized state with somewhat higher average density. This system thus undergoes the transition from the spin-unpolarized state to the spin polarized state and the corresponding critical value of r(s) estimated from the average density is as low as r(s) similar to 0.4 which is much smaller than the r(s) value for the Wigner lattice formation. When we compare the energies of spin-unpolarized and spin-polarized states for given average density, our data give the critical r(s) value for the transition between unpolarized and polarized states around 10 which is close to but still smaller than the known possibility of polarization at r(s) similar to 27. The advantage of our method is a direct applicability to geometrically complex systems which are difficult to analyze by integral equations and this is an example. (C) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physleta.2008.08.036

    Web of Science

    researchmap

  • Vibrational Properties of Si Crystal with Vacancy: A Tight-Binding Study

    Takafumi Ogawa, Kenji Tsuruta, Chieko Totsuji, Hiroo Totsuji, Hiroshi Iyetomi

    Memoirs of the Faculty of Engineering, Okayama University   42 ( 1 )   44 - 47   2008.1

     More details

    Language:English   Publishing type:Research paper (bulletin of university, research institution)   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • Nickel-related defect in diamond: A tight-binding molecular-dynamics study Reviewed

    Kenji Tsuruta, Satoshi Emoto, Chieko Totsuji, Hiroo Totsuji

    COMPUTATIONAL MATERIALS SCIENCE   38 ( 4 )   873 - 882   2007.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Structural, electronic, and magnetic properties of isolated Ni impurities at point defects and a dislocation core in diamond are investigated using tight-binding molecular-dynamics simulations. The results show the structural stabilization associated by lowering local symmetry in the cases of point defects. The segregation energies of Ni impurity for a substitutional site and for an interstitial site in the dislocation core are estimated to be in the same order within 0.2 eV. The local electronic density-of-states reveals that the gap states appeared by the insertion of Ni impurity are strongly localized around the Ni sites. Magnetic moments on neighboring C atoms are induced so as to screen the moment on the Ni atom except for the case of interstitial Ni impurity in which the total magnetic moment remains non-zero. Analyses indicate that localized atomic d states on the Ni atom and the p-d coupling between Ni and neighboring C atoms are responsible for the residual magnetic moment in the system with an interstitial Ni defect. In the other systems investigated, on the other hand, the bonding states between Ni impurity and its neighboring C atoms are dominated by the s-p coupling. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.commatsci.2006.06.003

    Web of Science

    researchmap

  • Two-step melting of spherical Yukawa and Coulomb clusters Reviewed

    Takafumi Ogawa, Hiroo Totsuji, Chieko Totsuji, Kenji Tsuruta

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   75 ( 12 )   2006.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PHYSICAL SOC JAPAN  

    By extensive Monte Carlo simulations, two separate peaks are found in the specific heat of relatively small spherical clusters of particles with 100 &lt; N &lt; 400, interacting via the Yukawa and Coulomb potentials and confined in the external field. The analyses of the diffusion and positional fluctuations show that these peaks at lower and higher temperatures reflect the loss of intrashell two-dimensional ordering and of the radial ordering, respectively. The magnitudes of the fluctuations in the outermost shell are consistent with the conventional Lindemann criterion. The results can be verified by experiments in ion traps and in dusty plasmas under microgravity or equivalent isotropic environments.

    DOI: 10.1143/JPSJ.75.123501

    Web of Science

    researchmap

  • Structure of spherical Yukawa clusters Reviewed

    Hiroo Totsuji, Takafumi Ogawa, Chieko Totsuji, Kenji Tsuruta

    Journal of Physics A: Mathematical and General   39 ( 17 )   4545   2006.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/0305-4470/39/17/S36

    Web of Science

    Scopus

    researchmap

  • Dynamics of melting of spherical Yukawa and Coulomb clusters Reviewed

    Takafumi Ogawa, Hiroo Totsuji, Chieko Totsuji, Kenji Tsuruta

    NON-NEUTRAL PLASMA PHYSICS VI   862   242 - 247   2006

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    Spherical Yukawa and Coulomb clusters are composed of charged particles interacting via the Yukawa and Coulomb potential and confined by the external potential. Melting transitions of these clusters are analyzed by Monte Carlo (MC) and molecular dynamics (MD) simulations. By MC simulations, it is found that the specific heat of relatively small clusters (100 &lt;= N &lt;= 400) has two peaks. The diffusion analyses by MC and MD simulations and the fluctuation analyses related to the Lindemann criteria indicate that two peaks at lower and higher temperatures reflect the losses in ordering in azimuthal and radial directions, respectively.

    DOI: 10.1063/1.2387929

    Web of Science

    researchmap

  • Structure and thermodynamics of spherical Yukawa and Coulomb clusters Reviewed

    Hiroo Totsuji, Takafumi Ogawa, Chieko Totsuji, Kenji Tsuruta

    NON-NEUTRAL PLASMA PHYSICS VI   862   232 - 241   2006

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    Structures in the ground state and thermodynamics related to melting of spherical Yukawa and Coulomb clusters confined in external fields of less than 103 particles are discussed on the basis of molecular dynamics and Monte Carlo simulations and theoretical methods. At low temperatures, particles form concentric shell structures which are expressed by simple formulas and insensitive to the strength of screening. Structures are reproduced by the shell model when the intrashell cohesive energy is properly taken into account. The specific heat of clusters of relatively small sizes 100 &lt;= N-d &lt;= 400 has two peaks as a function of temperature. By analyses of diffusions, it is shown that the peaks at lower and higher temparatures corresponds to the loss of ordering in the azimuthal and radial (and therefore total) ordering, respectively. Magnitudes of fluctuations in the outermost shell are consistent with the conventional Lindemann criterion.

    DOI: 10.1063/1.2387928

    Web of Science

    researchmap

  • Structure of finite two-dimensional systems of dust particles at finite temperatures Reviewed

    H Totsuji, C Totsuji, MS Liman, K Tsuruta

    PHYSICS OF PLASMAS   12 ( 10 )   2005.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    The structure of confined two-dimensional systems of dust particles in dusty plasmas is analyzed at finite temperatures by numerical simulations and theoretical approaches. The finite Yukawa system is adopted as a model for these systems and the variational method which has been successful in reproducing structures at low temperatures is extended to finite temperatures through replacement of the cohesive energy by the Helmholtz free energy recently given in the form of simple interpolation formulas. The results are compared with those of numerical simulations and their satisfactory agreement has been obtained. Finite-temperature structures presented here will be useful to evaluate the physical parameters of the two-dimensional systems of dust particles often formed near the boundary between the plasma bulk and the sheath.

    DOI: 10.1063/1.2116827

    Web of Science

    researchmap

  • Structure of spherical Yukawa clusters: A model for dust particles in dusty plasmas in an isotropic environment Reviewed

    Hiroo Totsuji, Takafumi Ogawa, Chieko Totsuji, Kenji Tsuruta

    Physical Review E   72 ( 3 )   036406   2005.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1103/PhysRevE.72.036406

    CiNii Article

    researchmap

  • Ordering of dust particles in dusty plasmas under microgravity Reviewed

    Hiroo Totsuji, Chieko Totsuji, Takafumi Ogawa, Kenji Tsuruta

    Physical Review E   71 ( 4 )   045401   2005.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1103/PhysRevE.71.045401

    CiNii Article

    researchmap

  • Thermodynamics of a two-dimensional Yukawa fluid Reviewed

    H Totsuji, MS Liman, C Totsuji, K Tsuruta

    PHYSICAL REVIEW E   70 ( 1 )   2004.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER PHYSICAL SOC  

    Thermodynamic quantities of a two-dimensional Yukawa system, a model for various systems including single-layered dust particles observed in dusty plasmas, are obtained and expressed by simple interpolation formulas. In the domain of weak coupling, the analytical method based on the cluster expansion is applied and, in the domain of intermediate and strong coupling, numerical simulations are performed. Due to reduced dimensionality, the treatment based on the mean field fails at the short range and exact behavior of the binary correlation is to be taken into account even in the case of weak coupling.

    DOI: 10.1103/PhysRevE.70.016405

    Web of Science

    researchmap

  • Thermodynamics of a two-dimensional Yukawa fluid Reviewed

    Hiroo Totsuji, M. Sanusi Liman, Chieko Totsuji, Kenji Tsuruta

    Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics   70 ( 1 )   7   2004

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Thermodynamic quantities of a two-dimensional Yukawa system, a model for various systems including single-layered dust particles observed in dusty plasmas, are obtained and expressed by simple interpolation formulas. In the domain of weak coupling, the analytical method based on the cluster expansion is applied and, in the domain of intermediate and strong coupling, numerical simulations are performed. Due to reduced dimensionality, the treatment based on the mean field fails at the short range and exact behavior of the binary correlation is to be taken into account even in the case of weak coupling. © 2004 The American Physical Society.

    DOI: 10.1103/PhysRevE.70.016405

    Scopus

    researchmap

  • Estimation of screening length and electric charge on particles in single-layered dusty plasma crystals (vol 68, art no. 017401, 2003) Reviewed

    C Totsuji, MS Liman, K Tsuruta, H Totsuji

    PHYSICAL REVIEW E   68 ( 4 )   2003.10

     More details

    Language:English   Publisher:AMER PHYSICAL SOC  

    DOI: 10.1103/PhysRevE.68.049901

    Web of Science

    researchmap

  • Estimation of screening length and electric charge on particles in single-layered dusty plasma crystals Reviewed

    C Totsuji, MS Liman, K Tsuruta, H Totsuji

    PHYSICAL REVIEW E   68 ( 1 )   499011   2003.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER PHYSICAL SOC  

    Single-layered two-dimensional crystals of dust particles are often observed in dusty plasma experiments and the data on their structure can be obtained by analyzing the images usually taken by charge-cupled device cameras. We give here some formulas for practical purposes of estimating the screening length and the electric charge on a dust particle from the surface density and the radius of such finite two-dimensional dust crystals. The formulas are derived on the basis of our theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas. An example of application is also shown.

    DOI: 10.1103/PhysRevE.68.017401

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Estimation of screening length and electric charge on particles in single-layered dusty plasma crystals Reviewed

    Chieko Totsuji, M. Sanusi Liman, Kenji Tsuruta, Hiroo Totsuji

    Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics   68 ( 1 )   4   2003

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Single-layered two-dimensional crystals of dust particles are often observed in dusty plasma experiments and the data on their structure can be obtained by analyzing the images usually taken by charge-cupled device cameras. We give here some formulas for practical purposes of estimating the screening length and the electric charge on a dust particle from the surface density and the radius of such finite two-dimensional dust crystals. The formulas are derived on the basis of our theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas. An example of application is also shown. © 2003 The American Physical Society.

    DOI: 10.1103/PhysRevE.68.017401

    Scopus

    researchmap

  • Competition between two forms of ordering in finite Coulomb clusters Reviewed

    H Totsuji, T Kishimoto, C Totsuji, K Tsuruta

    PHYSICAL REVIEW LETTERS   88 ( 12 )   2002.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMERICAN PHYSICAL SOC  

    The lowest-energy state of spherical clusters made up of single-species charged particles in a three-dimensional confining potential is investigated by molecular dynamics simulations for a system size of 5 x 10(3) to 1.2 x 10(5). The energy per particle is compared between shell-structured clusters and spherical finite-bcc lattices with relaxed surfaces. The shell structure in the interior is the lowest-energy configuration for ion numbers lower than about 10(4), while for higher ion numbers, an interior with bcc ordering surrounded by a few shells on the outside has lower energy. The formation of a small bcc lattice (nucleation) in the shell-structured cluster of 2 x 10(4) ions is observed.

    DOI: 10.1103/PhysRevLett.88.125002

    Web of Science

    researchmap

  • Dusty plasmas under microgravity Reviewed

    H Totsuji, C Totsuji, T Kishimoto, K Tsuruta

    NON-NEUTRAL PLASMA PHYSICS IV   606   201 - 206   2002

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    The structures of Yukawa systems spherically confined under the condition of micro-gravity are analyzed by molecular dynamics simulations. It is shown that the system is separated into the outer and the inner parts and well-developed shells appear in the outer part at low temperatures. In the case of Yukawa mixtures, there occurs the separation of species according to the magnitude of charges.

    Web of Science

    researchmap

  • Collaborative Simulation Grid: Multiscale Quantum-Mechanical/Classical Atomistic Simulations on Distributed PC Clusters in the US and Japan Reviewed

    H. Kikuchi, R. K. Kalia, A. Nakano, P. Vashishta, H. Iyetomi, S. Ogata, T. Kouno, F. Shimojo, K. Tsuruta, S. Saini

    Proceedings of the IEEE/ACM Supercomputing (SC) 2002 Conference (IEEE Computer Society, Los Alamitos, CA, 2002)   63 - 70   2002

     More details

    Publishing type:Research paper (international conference proceedings)  

    researchmap

  • Structure and Madelung energy of coulomb clusters Reviewed

    H Totsuji, T Kishimoto, C Totsuji, K Tsuruta

    NON-NEUTRAL PLASMA PHYSICS IV   606   181 - 190   2002

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    The ground state of the system of charged particles of one species confined by the three-dimensional, isotropic, and parabolic potential is investigated by molecular dynamics simulations. It is shown that, with the increase of the system size or the number of particles in the system N, the ground state changes from the shell-structured system to the finite bee lattice with reconstructed surface. The critical value of the transition is estimated to be between N = 10(4) and N = 2 x 10(4). The nucleation of the bee lattice in the she I I- structured cluster of 2 x 10(4) ions is observed.

    Web of Science

    researchmap

  • Structure of finite two-dimensional Yukawa lattices: Dust crystals Reviewed

    H Totsuji, C Totsuji, K Tsuruta

    PHYSICAL REVIEW E   64 ( 6 )   2001.12

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER PHYSICAL SOC  

    Dust particles in plasmas are often confined near the boundary between the plasma bulk and the sheath where the gravitation is balanced by electrostatic force. To keep dust particles from running away horizontally, an electrostatic potential is usually applied to the electrode surrounding these dusty plasmas and, under appropriate conditions. we have finite two-dimensional lattices of dust particles. Modeling the interaction between dust particles as the isotropic Yukawa interaction, structures of finite two-dimensional Yukawa systems at low temperatures have been analyzed both by numerical simulations and variational methods. The effect of the correlation energy between dust particles is shown to play an important role in the formation of the one-body distribution in these systems.

    DOI: 10.1103/PhysRevE.64.066402

    Web of Science

    researchmap

  • Parallel tight-binding molecular dynamics for high-temperature neck formation processes of nanocrystalline silicon carbide Reviewed

    K Tsuruta, H Totsuji, C Totsuji

    MATERIALS TRANSACTIONS   42 ( 11 )   2261 - 2265   2001.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN INST METALS  

    Tight-binding molecular dynamics (TBMD) simulations are performed to investigate atomic and electronic structures during neck formation processes of nanocrystalline silicon carbide at high temperature. For calculating the electronic energy and forces we use a linear-scaling method (the Fermi-operator expansion method) with a scalable parallel algorithm. The TBMD simulations of collision of SiC nanospheres show that processes of neck formation depend strongly on contact angles between the two grains. Electronic populations at grain boundaries are rather uniform, even in a disordered structure of the grain boundary between misaligned nanospheres, Atomic diffusions at elevated temperature are, on the other hand, quite different in the necks formed with different orientations of particles.

    Web of Science

    researchmap

  • Neck formation processes of nanocrystalline silicon carbide: a tight-binding molecular dynamics study Reviewed

    K Tsuruta, H Totsuji, C Totsuji

    PHILOSOPHICAL MAGAZINE LETTERS   81 ( 5 )   357 - 366   2001.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:TAYLOR & FRANCIS LTD  

    Atomistic and electronic structures in the process of intergranular neck formation of nanocrystalline silicon carbide (SiC) have been investigated by a tight-binding molecular dynamics method. An order-N parallel algorithm is employed for efficient calculations of electronic energy and forces. We find that a defect-free neck is formed between SIC nanocrystals aligned along [11 (2) over bar] axis at T = 1000 K. In the case of neck formation between tilted nanocrystals (with an orientation equivalent to a {122}, Sigma = 9 grain boundary), surface reconstruction before sintering, that is Si-Si bond formation, significantly affects the grain-boundary formation. The spatial distribution of the electronic population and the electronic density of states show that structural defects, accompanied by gap states, are formed around the reconstructed regions after the sintering.

    Web of Science

    researchmap

  • On the Madelung energy of spherical Coulomb clusters Reviewed

    T Kishimoto, C Totsuji, K Tsuruta, H Totsuji

    PHYSICS LETTERS A   281 ( 4 )   256 - 259   2001.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    We perform large-scale molecular dynamics (MD) simulations of Coulomb clusters in a spherical trapping field. The fast multipole method have been employed to simulate clusters of up to 5 x 10(4) particles while previous investigations are limited to clusters of less than 5000 particles, It is found that the Madelung energy of bce clusters with reconstructed surfaces is substantially smaller than the extrapolated values based on the previous results for smaller multilayered icosahedral clusters. (C) 2001 Elsevier Science B.V. All rights reserved.

    Web of Science

    researchmap

  • Yukawa mixtures with and without gravity Reviewed

    H Totsuji, T Kishimoto, C Totsuji, K Tsuruta

    PHYSICA SCRIPTA   T89   117 - 121   2001

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ROYAL SWEDISH ACAD SCIENCES  

    The structures of systems of particles with repulsive Yukawa interactions are analyzed by molecular dynamics simulations with emphasis on the behavior of Yukawa mixtures. To keep the density of particles with mutual repulsion at finite values, we need some confining mechanism and the latter has strong effects on the structure formation. Under the gravity, the confinement is one-dimensional and we have layered structures. In this case, Yukawa mixtures are separated by the difference in the charge to mass ratios. In the case without gravity, we may have three-dimensional confinement and the behavior of the system may be analyzed by assuming spherical symmetry. We show that there also occurs a separation of species according to the magnitude of charges under the condition of no gravity and we have well-organized structures when the temperature is sufficiently low.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Initial stages of sintering of TiO<inf>2</inf>nanoparticles: Variable-charge molecular dynamics simulations Reviewed

    Ogata S, Iyetomi H, Tsuruta K, Shimojo F, Nakano A, Vashishta P, Kalia R.K, Loong C.-K

    Materials Research Society Symposium - Proceedings   634   B7.6.1 - B7.6.6   2001

     More details

    Publishing type:Research paper (scientific journal)  

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Structure of finite two-dimensional Yukawa lattices: Dust crystals Reviewed

    Hiroo Totsuji, Chieko Totsuji, Kenji Tsuruta

    Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics   64 ( 6 )   7   2001

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Dust particles in plasmas are often confined near the boundary between the plasma bulk and the sheath where the gravitation is balanced by electrostatic force. To keep dust particles from running away horizontally, an electrostatic potential is usually applied to the electrode surrounding these dusty plasmas and, under appropriate conditions, we have finite two-dimensional lattices of dust particles. Modeling the interaction between dust particles as the isotropic Yukawa interaction, structures of finite two-dimensional Yukawa systems at low temperatures have been analyzed both by numerical simulations and variational methods. The effect of the correlation energy between dust particles is shown to play an important role in the formation of the one-body distribution in these systems. © 2001 The American Physical Society.

    DOI: 10.1103/PhysRevE.64.066402

    Scopus

    researchmap

  • Yukawa Mixtures with and without Gravity

    Hiroo Totsuji, Tokunari Kishimoto, Chieko Totsuji, Kenji Tsuruta

    Physica Scripta   T89 ( 1 )   117 - 117   2001

     More details

    Publishing type:Research paper (scientific journal)   Publisher:IOP Publishing  

    DOI: 10.1238/physica.topical.089a00117

    researchmap

  • A scalable molecular-dynamics algorithm suite for materials simulations: design-space diagram on 1024 Cray T3E processors Reviewed

    F Shimojo, TJ Campbell, RK Kalia, A Nakano, P Vashishta, S Ogata, K Tsuruta

    FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE   17 ( 3 )   279 - 291   2000.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    A suite of scalable molecular-dynamics (MD) algorithms has been developed for materials simulations. The linear scaling MD algorithms encompass a wide spectrum of physical reality: (i) classical MD based on a many-body interatomic potential model; (ii) environment-dependent, variable-charge MD: (iii) quantum mechanical MD based on the tight-binding method; and (iv) self-consistent quantum MD based on the density functional theory. Benchmark tests on 1024 Gray T3E processors including 1.02-billion-atom many-body and 22 500-atom density functional MD simulations demonstrate that these algorithms are highly scalable. A design-space diagram spanning seven decades of system size and computational time is constructed for materials scientists to design an optimal MD simulation incorporating maximal physical realism within a given computational budget. (C) 2000 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0167-739X(00)00087-X

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Role of atomic charge transfer on sintering of TiO2 nanoparticles: Variable-charge molecular dynamics Reviewed

    S Ogata, H Iyetomi, K Tsuruta, F Shimojo, A Nakano, RK Kalia, P Vashishta

    JOURNAL OF APPLIED PHYSICS   88 ( 10 )   6011 - 6015   2000.11

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    The stability of surface structure and space-charge distribution in free TiO2 nanoparticles are investigated for both rutile and anatase phases using a variable-charge interaction potential in which atomic charges vary dynamically depending on their environment. We find the dynamic charge transfer: (i) enhances atomic diffusion at surfaces of the spherical nanoparticles at high temperatures; and (ii) creates additional repulsive force between the two nanospheres through formation of a double-charge surface layer in each nanosphere. The surface diffusion due to the charge transfer clearly distinguishes the two nanospheres with different underlying crystalline structures; the surface diffusion constant of the anatase sphere is almost three times as great as that of the rutile sphere. Variable-charge molecular dynamics simulations are then applied to sintering of two TiO2 nanospheres. It turns out that the enhanced surface diffusion in the anatase nanosphere at high temperatures significantly promotes neck formation between the two spheres. (C) 2000 American Institute of Physics. [S0021-8979(00)08323-7].

    DOI: 10.1063/1.1321785

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Sintering, structure, and mechanical properties of nanophase SiC: A molecular-dynamics and neutron scattering study Reviewed

    A Chatterjee, RK Kalia, A Nakano, A Omeltchenko, K Tsuruta, P Vashishta, CK Loong, M Winterer, S Klein

    APPLIED PHYSICS LETTERS   77 ( 8 )   1132 - 1134   2000.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    Structure, mechanical properties, and sintering of nanostructured SiC (n-SiC) are investigated with neutron scattering and molecular-dynamics (MD) techniques. Both MD and the experiment indicate the onset of sintering around 1500 K. During sintering, the pores shrink while maintaining their morphology: the fractal dimension is similar to 2 and the surface roughness exponent is similar to 0.45. Structural analyses reveal that interfacial regions in n-SiC are disordered with nearly the same number of three- and fourfold coordinated Si atoms. The elastic moduli scale with the density as similar to rho(mu), where mu=3.4 +/- 0.1. (C) 2000 American Institute of Physics. [S0003-6951(00)04334-5].

    Web of Science

    researchmap

  • Strongly coupled nonneutral plasmas: Equilibrium and relaxation in two-component plasmas in Penning-Malmberg trap Reviewed

    H Totsuji, K Tsuruta, C Totsuji, K Nakano, T Kishimoto, K Kamon

    JOURNAL DE PHYSIQUE IV   10 ( P5 )   271 - 274   2000.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:E D P SCIENCES  

    The relaxation processes and the equilibrium distribution of two-component nonneutral plasmas in the Penning-Malmberg trap are analyzed by molecular dynamics simulations and theoretical approaches. As an example, mixtures of antiprotons and electrons for antiproton cooling experiments are considered. The relaxation of antiproton energy is calculated based on the rate equations and it is shown that the slow energy transfer between parallel and perpendicular components of strongly magnetized electrons does not affect the whole relaxation process seriously. The equilibrium distribution of each species are obtained by extensive molecular dynamics simulations for various values of parameters and the results are reproduced by theoretical calculations to a good accuracy. The condition for the centrifugal separation is obtained.

    DOI: 10.1051/jp4:2000549

    Web of Science

    researchmap

  • Large scale quantum simulations of strongly coupled plasmas on a PC cluster Reviewed

    H Totsuji, K Tsuruta, C Totsuji

    JOURNAL DE PHYSIQUE IV   10 ( P5 )   267 - 270   2000.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:E D P SCIENCES  

    As a method of quantum simulation for large systems with surfaces and inhomogenieties, the density functional molecular dynamics is applied to the hydrogen plasma in the domain of liquid metallic hydrogen and the performance of a PC cluster is measured. Usefulness of relatively small scale PC cluter is shown even without much efforts in tuning the programs for parallel computation.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Structure and dynamics of Yukawa dusty plasmas and dusty plasma mixtures Reviewed

    C. Totsuji, H. Totsuji, K. Tsuruta, K. Kamon, T. Kishimoto, T. Sasabe

    Le Journal de Physique IV   10 ( PR5 )   Pr5 - 425   2000.3

     More details

    Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

    DOI: 10.1051/jp4:2000582

    researchmap

  • Structures and structural transitions in strongly-coupled Yukawa dusty plasmas and mixtures Reviewed

    H Totsuji, C Totsuji, K Tsuruta

    FRONTIERS IN DUSTY PLASMAS   141 - 146   2000

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:ELSEVIER SCIENCE BV  

    Regarded as Yukawa systems in external confining potentials, structures and transitions in dusty plasmas have been analyzed theoretically and by numerical simulations. The one-dimensional confinement in three dimensions and the radial confinement in two dimensions are considered. The results of simulations have been reproduced to a good accuracy in both cases. It is shown that the inclusion of the correlation energy or the effect of strong coupling is of essential importance in the theory. A crossover from the surface freezing of Coulomb system to surface melting of systems of short-ranged interactions is observed.

    Web of Science

    researchmap

  • Intercluster interaction of TiO2 nanoclusters using variable-charge interatomic potentials Reviewed

    S Ogata, H Iyetomi, K Tsuruta, F Shimojo, RK Kalia, A Nakano, P Vashishta

    NANOPHASE AND NANOCOMPOSITE MATERIALS III   581   667 - 672   2000

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOCIETY  

    A new interatomic potential has been developed for molecular-dynamics simulations of TiO2 based on the formalism of Streitz and Mintmire [J. Adhesion Sci. Technol. 8, 853 (1994)], in which atomic charges vary dynamically according to the generalized electronegativity-equalization principle. The present potential reproduces various quantities of rutile crystal including vibrational density of states, static dielectric constants, melting temperature, elastic moduli, and surface relaxation. Calculated cohesive-energy and dielectric constants for anatase crystal agree well with experimental data The potential is applied to TiO2 nanoclusters (size 60-80 Angstrom) for both anatase and rutile phases to analyze their equilibrium configuration and space-charge distribution. Stable double-charge layer is found in the surface region of a spherical nanocluster for both rutile and anatase, resulting in enhanced Coulomb-repulsion between the nanoclusters at close proximity.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Variable-charge interatomic potentials for molecular-dynamics simulations of TiO2 Reviewed

    S Ogata, H Iyetomi, K Tsuruta, F Shimojo, RK Kalia, A Nakano, P Vashishta

    JOURNAL OF APPLIED PHYSICS   86 ( 6 )   3036 - 3041   1999.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER INST PHYSICS  

    An interatomic potential model has been developed for molecular-dynamics simulations of TiO2 (rutile) based on the formalism of Streitz and Mintmire [J. Adhes. Sci. Technol. 8, 853 (1994)], in which atomic charges vary dynamically according to the generalized electronegativity equalization principle. The present model potential reproduces the vibrational density of states, the pressure-dependent static dielectric constants, the melting temperature, and the surface relaxation of the rutile crystal, as well as the cohesive energy, the lattice constants, and the elastic moduli. We find the physical properties of rutile are significantly affected by dynamic charge transfer between Ti and O atoms. The potential allows us to perform atomistic simulations on nanostructured TiO2 with various kinds of interfaces (surfaces, grain boundaries, dislocations, etc.). (C) 1999 American Institute of Physics. [S0021-8979(99)07618-5].

    DOI: 10.1063/1.371165

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Parallel molecular dynamics simulations of high temperature ceramics Reviewed

    A Chatterjee, T Campbell, RK Kalia, A Nakano, A Omeltchenko, K Tsuruta, P Vashishta, S Ogata

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   19 ( 13-14 )   2257 - 2264   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    'Grand Challenge' atomistic simulations of high-temperature structural materials ave performed on multiple, parallel platforms. The simulations focus on sintering of ceramic nanoclusters, structure and mechanical properties of nanophase ceramics, and hypervelocity impact damage in diamond coatings. (C) 1999 Elsevier Science Ltd. All rights reserved.

    Web of Science

    researchmap

  • Structures and dynamics of dusty plasmas and dusty plasma mixtures Reviewed

    H Totsuji, C Totsuji, K Tsuruta, K Kamon, T Kishimoto, T Sasabe

    NON-NEUTRAL PLASMA PHYSICS III   498   389 - 394   1999

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    Dusty plasmas can be regarded as assemblies of Yukawa particles in a one-dimensional potential well. We extend the analyses on dusty plasmas in two directions: the two-dimensional Yukawa system and Yukawa mixtures. (1) Under appropriate conditions at low temperatures, dust particles sit in a plane which is perpendicular to the gravitational field. When they are also confined laterally by an electrode, we have a finite two-dimensional system of Yukawa particles. The low temperature structures are obtained by molecular dynamics simulations and the results are reproduced by theoretical analyses. Through these analyses we show that the correlation energy of the Yukawa system plays an essential role in structure formations. As for dynamics of this system, a crossover from the surface freezing of Coulomb system to surface melting of systems of short-ranged interactions is observed. (2) In the case of mixtures, we have an extra parameter characterizing the difference in the gravity on each species. We obtain the low temperature structures of this system and compare them with theoretical predictions based on the results for the case of one component.

    Web of Science

    researchmap

  • Two-component nonequilibrium nonneutral plasma in Penning-Malmberg trap Reviewed

    H Totsuji, K Tsuruta, C Totsuji, K Nakano, K Kamon, T Kishimoto

    NON-NEUTRAL PLASMA PHYSICS III   498   77 - 82   1999

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AMER INST PHYSICS  

    The behavior of the two-component nonneutral plasma in the Penning Malmberg trap is analyzed by simulations and theoretical approaches. The parameters expected in experiments of antiproton cooling by electrons are assumed. The relaxation of antiproton energy is followed by the rate equation with proper account taken into account for the slow transfer of energy between parallel and perpendicular components of strongly magnetized electrons. The equilibrium distribution of each species are obtained by molecular dynamics simulations for various Values of parameters and the results are reproduced by theoretical calculations to a good accuracy. The condition for the centrifugal separation is obtained.

    Web of Science

    researchmap

  • Structural correlations and mechanical behavior in nanophase silica glasses Reviewed

    T. J. Campbell, R. K. Kalia, A. Nakano, F. Shimojo, K. Tsuruta, P. Vashishta, S. Ogata

    Physical Review Letters   82 ( 20 )   4018 - 4021   1999

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Physical Society  

    DOI: 10.1103/PhysRevLett.82.4018

    CiNii Article

    CiNii Books

    researchmap

  • Structure and dynamics of consolidation and fracture in nanophase ceramics via parallel molecular dynamics Reviewed

    K Tsuruta, JH Wang, A Omeltchenko, A Nakano, RK Kalia, P Vashishta

    COMPUTER-AIDED DESIGN OF HIGH-TEMPERATURE MATERIALS   323 - 332   1999

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:OXFORD UNIV PRESS  

    Web of Science

    researchmap

  • Structural correlations and stress distribution at silicon/silicon nitride interface Reviewed

    ME Bachlechner, A Omeltchenko, K Tsuruta, A Nakano, RK Kalia, P Vashishta, Ebbsjo, I, A Madhukar

    COMPUTER-AIDED DESIGN OF HIGH-TEMPERATURE MATERIALS   244 - 255   1999

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:OXFORD UNIV PRESS  

    Web of Science

    researchmap

  • Dynamic fracture in nanophase ceramics and diamond films: Multimillion atom parallel molecular-dynamics simulations Reviewed

    A Omeltchenko, K Tsuruta, A Nakano, R Kalia, P Vashishta, O Shenderova, DW Brenner

    COMPUTER-AIDED DESIGN OF HIGH-TEMPERATURE MATERIALS   81 - 104   1999

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:OXFORD UNIV PRESS  

    Web of Science

    researchmap

  • Atomistic simulation of nanostructured materials Reviewed

    A Nakano, ME Bachlechner, TJ Campbell, RK Kalla, A Omeltchenko, K Tsuruta, P Vashishta, S Ogata, Ebbsjo, I, A Madhukar

    IEEE COMPUTATIONAL SCIENCE & ENGINEERING   5 ( 4 )   68 - 78   1998.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE COMPUTER SOC  

    Materials and devices with microstructures on the nanometer scale are revolutionizing technology, but until recently simulation at this scale has bean problematic. Developments in parallel computing are now allowing atomistic simulation using multiresolution algorithms, such as fast multipole methods. With these algorithms, researchers may soon be able to simulate applications up to one billion atoms.

    DOI: 10.1109/99.735897

    Web of Science

    researchmap

  • Dynamics of consolidation and crack growth in nanocluster-assembled amorphous silicon nitride Reviewed

    K Tsuruta, A Nakano, RK Kalia, P Vashishta

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   81 ( 2 )   433 - 436   1998.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER CERAMIC SOC  

    Consolidation and fracture dynamics in nanophase amorphous Si3N4 are investigated using 10(6)-atom molecular-dynamics simulations. At a pressure of 15 GPa and 2000 K, the nanophase system is almost fully consolidated within a fraction of a nanosecond. The consolidation process is well-described by the classical theory of sintering. Under an applied strain the consolidated system develops several cracks which propagate parallel to each other, causing failure at multiple sites. The critical strain at which the nanophase system fractures is much larger than that for crystalline Si3N4.

    Web of Science

    researchmap

  • Oxidation dynamics of nanophase aluminum clusters: A molecular dynamics study Reviewed

    S Ogata, TJ Campbell, K Tsuruta, A Nakano, RK Kalia, P Vashishta, CK Loong

    PHASE TRANSFORMATIONS AND SYSTEMS DRIVEN FAR FROM EQUILIBRIUM   481   625 - 630   1998

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOCIETY  

    Oxidation of an aluminum nanocluster (252,158 atoms) of radius 100 Angstrom placed in gaseous oxygen (530,727 atoms) is investigated by performing molecular-dynamics simulations on parallel computers. The simulation takes into account the effect of charge transfer between Al and O based on the electronegativity equalization principles. We find that the oxidation starts at the surface of the cluster and the oxide layer grows to a thickness of similar to 28 Angstrom. Evolutions of local temperature and densities of Al and O are investigated. The surface oxide melts because of the high temperature resulting from the release of energy associated with Al-O bondings. Amorphous surface-oxides are obtained by quenching the cluster. Vibrational density-of-states for the surface oxide is analyzed through comparisons with those for crystalline Al, Al nanocluster, and alpha-Al2O3.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Role of ultrafine microstructures in dynamic fracture in nanophase silicon nitride Reviewed

    RK Kalia, A Nakano, A Omeltchenko, K Tsuruta, P Vashishta

    PHYSICAL REVIEW LETTERS   78 ( 11 )   2144 - 2147   1997.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMERICAN PHYSICAL SOC  

    Using 10(6)-atom molecular-dynamics simulations, we investigate dynamic fracture in nanophase Si3N4. The simulations reveal that intercluster regions are amorphous, and they deflect cracks and give rise to local crack branching. As a result, the nanophase system is able to sustain an order-of-magnitude larger external strain than crystalline Si3N4. We also determine the morphology of fracture surfaces: For in-plane fracture surface profiles the roughness exponent zeta = 0.57 and for out-of-plane profiles the exponents zeta(perpendicular to) = 0.84 and zeta(parallel to) = 0.75 are in excellent agreement with experiments.

    Web of Science

    researchmap

  • Morphology of pores and interfaces and mechanical behavior of nanocluster-assembled silicon nitride ceramic Reviewed

    RK Kalia, A Nakano, K Tsuruta, P Vashishta

    PHYSICAL REVIEW LETTERS   78 ( 4 )   689 - 692   1997.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMERICAN PHYSICAL SOC  

    Million atom molecular-dynamics simulations are performed to investigate the structure, dynamics, and mechanical behavior of cluster-assembled Si3N4. These solids contain highly disordered interfacial regions with 50% undercoordinated atoms. Systems sintered at low pressures have percolating pores whose surface morphologies are well characterized by two values of the roughness exponent, 0.46 and 0.86; these are close to the experimental values found by Bouchaud et al. for fracture surfaces. Results for elastic moduli are consistent with a three-phase model for heterogeneous materials.

    Web of Science

    researchmap

  • Structure, mechanical properties, and dynamic fracture in nanophase silicon nitride via parallel molecular dynamics Reviewed

    K Tsuruta, A Omeltchenko, A Nakano, RK Kalia, P Vashishta

    NANOPHASE AND NANOCOMPOSITE MATERIALS II   457   205 - 210   1997

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOCIETY  

    Million-atom molecular-dynamics (MD) simulations are performed to study the structure, mechanical properties, and dynamic fracture in nanophase Si3N4. We find that intercluster regions are highly disordered: 50% of Si atoms in intercluster regions are three-fold coordinated. Elastic moduli of nanophase Si3N4 as a function of grain size and porosity are well described by a multiphase model for heterogeneous materials. The study of fracture in the nanophase Si3N4 reveals that the system can sustain an order-of-magnitude larger external load than crystalline Si3N4. This is due to branching and pinning of the crack front by nanoscale microstructures.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Million atom molecular dynamics simulation of nanophase silicon nitride Reviewed

    RK Kalia, A Nakano, A Omeltchenko, K Tsuruta, P Vashishta

    CHEMISTRY AND PHYSICS OF NANOSTRUCTURES AND RELATED NON-EQUILIBRIUM MATERIALS   89 - 96   1997

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MINERALS, METALS & MATERIALS SOC  

    Structural correlations and dynamic fracture in nanocluster-assembled silicon nitride are investigated with molecular-dynamics (MD) simulations involving 1.08 million particles. These simulations reveal that the consolidated nanophase Si3N4 has highly disordered intercluster regions that contain 50% under-coordinated atoms. Amorphous interfacial regions deflect cracks and give rise to local crack branching. These dissipative mechanisms enable the nanophase system to sustain an order-of-magnitude larger external strain than crystalline Si3N4. The morphology of fracture surfaces in nanophase Si3N4 is also determined. The MD results for roughness exponents are very close to experimental values even though the materials and length scales are very different.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Fracture of nanophase ceramics: A molecular-dynamics study Reviewed

    A Nakano, RK Kalia, A Omeltchenko, K Tsuruta, P Vashishta

    NANOPHASE AND NANOCOMPOSITE MATERIALS II   457   187 - 192   1997

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOCIETY  

    New multiscale algorithms and a load-balancing scheme are combined for molecular-dynamics simulations of nanocluster-assembled ceramics on parallel computers. Million-atom simulations of the dynamic fracture in nanophase silicon nitride reveal anisotropic self-affine structures and crossover phenomena associated with fracture surfaces.

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Million atom molecular dynamics simulations of materials on parallel computers Reviewed

    P Vashishta, RK Kalia, W Li, A Nakano, A Omeltchenko, K Tsuruta, JH Wang, Ebbsjo, I

    CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE   1 ( 6 )   853 - 863   1996.12

     More details

    Language:English   Publisher:CURRENT SCIENCE LTD  

    Recent advances in computing technology - parallel computer architectures, portable software and development of robust O(N) algorithms - have revolutionized the field of computer simulation. Using the space-time multiresolution molecular dynamics algorithms it is possible to carry out multimillion atom simulations of materials in different ranges of density, temperature and uniaxial strain.

    DOI: 10.1016/S1359-0286(96)80113-6

    Web of Science

    researchmap

  • Early stages of sintering of silicon nitride nanoclusters: A molecular-dynamics study on parallel machines Reviewed

    K Tsuruta, A Omeltchenko, RK Kalia, P Vashishta

    EUROPHYSICS LETTERS   33 ( 6 )   441 - 446   1996.2

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:EDITIONS PHYSIQUE  

    Sintering of Si3N4 nanoclusters is investigated With the molecular-dynamics approach. At 2000 K thermally rough nanocrystals develop an asymmetric neck in 100 picoseconds. The neck contains more fourfold than threefold coordinated Si atoms, Amorphous nanoclusters develop a symmetric neck which has nearly equal number of threefold and fourfold coordinated Si atoms. In both cases, sintering is driven by surface diffusion of Si and N atoms. The diffusion is much more rapid in the neck joining amorphous nanoclusters than in the neck region of nanocrystals.

    DOI: 10.1209/epl/i1996-00359-2

    Web of Science

    researchmap

  • Early stages of sintering of Si3N4 nanoclusters via parallel molecular dynamics Reviewed

    K Tsuruta, A Omeltchenko, RK Kalia, P Vashishta

    MATERIALS THEORY, SIMULATIONS, AND PARALLEL ALGORITHMS   408   181 - 186   1996

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOC  

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Sintering of amorphous Si3N4 nanoclusters: A molecular dynamics study of stress analysis Reviewed

    JH Wang, K Tsuruta, A Omeltchenko, RK Kalia, P Vashishta

    MATERIALS THEORY, SIMULATIONS, AND PARALLEL ALGORITHMS   408   573 - 578   1996

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:MATERIALS RESEARCH SOC  

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • Dense plasma as a statistical ensemble of Coulomb clusters: A new paradigm Reviewed

    K TSURUTA, S ICHIMARU

    NON-NEUTRAL PLASMA PHYSICS II   ( 331 )   252 - 261   1995

     More details

    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:AIP PRESS  

    Web of Science

    researchmap

  • Erratum: Short-range screening potentials for classical Coulomb fluids: Monte Carlo sampling and cluster model studies (Physical Review E (1995) 51, 4, (3788)) Reviewed

    Ichimaru S, Ogata S, Tsuruta K

    Physical Review E   51 ( 4 )   3788 - 3788   1995

     More details

    Publishing type:Research paper (scientific journal)  

    DOI: 10.1103/PhysRevE.51.3788

    Web of Science

    Scopus

    researchmap

    Other Link: http://orcid.org/0000-0002-1447-2530

  • SHORT-RANGE SCREENING POTENTIALS FOR CLASSICAL COULOMB FLUIDS - MONTE-CARLO SAMPLING AND CLUSTER MODEL STUDIES Reviewed

    S ICHIMARU, S OGATA, K TSURUTA

    PHYSICAL REVIEW E   50 ( 4 )   2977 - 2985   1994.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMERICAN PHYSICAL SOC  

    Screening potential, the balance between the bare Coulomb repulsion and the potential of mean force in a charged liquid, plays an essential role in the theoretical estimation of enhancement for the nuclear reaction rates in dense stellar matter. For the accurate assessment of the screening potential at short interparticle separations, we revisit the first-principles calculations for the coefficients of the Widom expansion and undertake extra-long Monte Carlo samplings in specifically designed binary-ionic systems. The results are compared with those obtained from an approximate estimation based on extrapolation from intermediate distances. We also present model calculations of the screening potential with two-ion clusters, which shed light on the relation between the short- and intermediate-range behaviors.

    Web of Science

    researchmap

  • BINDING-ENERGY, MICROSTRUCTURE, AND SHELL-MODEL OF COULOMB CLUSTERS Reviewed

    K TSURUTA, S ICHIMARU

    PHYSICAL REVIEW A   48 ( 2 )   1339 - 1344   1993.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMERICAN PHYSICAL SOC  

    By computer-simulation and analytic studies for binding energies and microscopic shell structures, it is shown that Coulomb clusters assume particularly stable configurations at certain ''magic numbers'' of particles. Through analyses with the spherical Voronoi numbers, a special role that the icosahedral geometry plays in shaping the particle configurations on the spherical surfaces is elucidated. Gross features in the cluster structures, such as the shell radii and intershell partition of particles, are well accounted for by an appropriate shell model.

    DOI: 10.1103/PhysRevA.48.1339

    Web of Science

    researchmap

  • Collisional equipartition rate for a magnetized pure electron plasma Reviewed

    Michael E. Glinsky, Thomas M. O'Neil, Marshall N. Rosenbluth, Kenji Tsuruta, Setsuo Ichimaru

    Physics of Fluids B   4 ( 5 )   1156 - 1166   1992

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    The collisional equipartition rate between the parallel and perpendicular velocity components is calculated for a weakly correlated electron plasma that is immersed in a uniform magnetic field. Here, parallel and perpendicular refer to the direction of the magnetic field. The rate depends on the parameter κ̄ = (b̄/rc)/√2, where rc = √T/m/Ωc is the cyclotron radius and b̄ = 2e 2/T is twice the distance of closest approach. For a strongly magnetized plasma (i.e., κ̄ ≫ 1), the equipartition rate is exponentially small (v∼exp[ -5(3πκ̄)2/5/6]). For a weakly magnetized plasma (i.e., κ̄ ≪ 1), the rate is the same as for an unmagnetized plasma except that rc/b̄ replaces λD/b̄ in the Coulomb logarithm. (It is assumed here that rc &lt
    λD
    for rc &gt
    λD, the plasma is effectively unmagnetized.) This paper contains a numerical treatment that spans the intermediate regime κ̄∼1, and connects onto asymptotic results in the two limits κ̄ ≪ 1 and κ̄ ≫ 1. Also, an improved asymptotic expression for the rate in the high-field limit is derived. The present theoretical results are in good agreement with recent measurements of the equipartition rate over eight decades in κ̄ and four decades in the scaled rate v/nv̄b̄2, where n is the electron density and v̄ = √2T/m. © 1992 American Institute of Physics.

    DOI: 10.1063/1.860124

    Scopus

    researchmap

▼display all

Books

  • 工学系の微分方程式(第8刷)

    岡山大学出版会  2020 

     More details

    Language:Japanese Book type:Textbook, survey, introduction

  • 工学系の微分方程式(第7刷)

    岡山大学出版会  2019 

     More details

    Language:Japanese Book type:Textbook, survey, introduction

  • 工学系の微分方程式(第6刷)

    岡山大学出版会  2018 

     More details

  • Differential Equation for Engineering

    Okayama University Press  2018 

     More details

  • 工学系の微分方程式(第5刷)

    岡山大学出版会  2017 

     More details

  • Differential Equation for Engineering

    Okayama University Press  2017 

     More details

  • Differential Equation for Engineering

    Okayama University Press  2013 

     More details

  • 工学系の微分方程式

    岡山大学出版会  2013 

     More details

  • 機能性微粒子とナノマテリアルの開発

    フロンティア出版  2004 

     More details

  • Inertial Fusion Sciences and Applications 2001, (Proceedings of the 2nd international conference on Inertial Fusion and Sciences and Applications (IFSA2001)

    Elsevier  2002 

     More details

  • NON-NEUTRAL PLASMA PHYSICS IV, (Proceedings of the Workshop on Non-Neutral Plasmas, San Diego, California 2001)

    AIP  2002 

     More details

  • Frontiers in Dusty Plasmas, Proceedings of the 2nd International Conference on the Physics of Dusty Plasmas (ICPDP-99)

    Elsevier  2000 

     More details

  • チェイキン&ルベンスキー現代の凝縮系物理学(下)

    吉岡書店  2000 

     More details

  • チェイキン&ルベンスキー現代の凝縮系物理学(上)

    吉岡書店  2000 

     More details

  • Proceedings of international conference on “Computer-Aided Design of High-Temperature Materials”

    Oxford Press  1999 

     More details

  • Non-Neutral Physics III

    American Institute of Physics  1999 

     More details

▼display all

MISC

  • Optical-Property Prediction of Digital Metamaterials with Reservoir Computing

    目黒智也, 佐藤郷介, 三澤賢明, 藤森和博, 鶴田健二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   72nd   2021

  • フォノニック結晶中の超音波伝搬と光学的可視化評価 (超音波)

    真鍋 健輔, 石川 篤, 神田 岳文, 鶴田 健二

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 155 )   67 - 69   2017.7

     More details

    Language:Japanese   Publisher:電子情報通信学会  

    CiNii Article

    CiNii Books

    researchmap

  • 超音波・弾性波の非相反伝搬機構の設計 Invited

    鶴田 健二

    超音波TECHNO   29 ( 6 )   70 - 73   2017.6

     More details

    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

    researchmap

  • メタ表面構造を用いた吸音およびエナジーハーべスティングデバイスの設計 (超音波)

    小林 祐太, 石川 篤, 鶴田 健二

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 169 )   15 - 17   2016.7

     More details

    Language:Japanese   Publisher:電子情報通信学会  

    CiNii Article

    CiNii Books

    researchmap

  • 1P1-8 Rectification of Lamb wave propagation in thin plates with piezo-dielectric periodic structures

    Iwasaki Yuhei, Tsuruta Kenji, Ishikawa Atsushi

    Proceedings of Symposium on Ultrasonic Electronics   36   "1P1 - 8-1"-"1P1-8-2"   2015.11

     More details

    Language:English   Publisher:Steering committee of symposium on ultrasonic electronics  

    CiNii Article

    CiNii Books

    researchmap

  • 3P1-7 Design of Acoustic Metasurface toward a Perfect Absorber

    Kobayashi Yuta, Tsuruta Kenji, Ishikawa Atsushi

    Proceedings of Symposium on Ultrasonic Electronics   36   "3P1 - 7-1"-"3P1-7-2"   2015.11

     More details

    Language:English   Publisher:Steering committee of symposium on ultrasonic electronics  

    CiNii Article

    CiNii Books

    researchmap

  • 302 Molecular dynamics analysis on graphite/resin interface modification

    YONEI Ryota, TSURUTA Kenji, ISHIKAWA Atsushi

    The Computational Mechanics Conference   2015 ( 28 )   "302 - 1"-"302-2"   2015.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 301 Design of Acoustic Metasurface toward a Perfect Sound Absorber

    Kobayashi Yuta, Tsuruta Kenji, Ishikawa Atsushi

    The Computational Mechanics Conference   2015 ( 28 )   "301 - 1"-"301-2"   2015.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • グラフェンプラズモニクス

    月刊OPTRONICS   34 ( 12 )   75 - 80   2015

     More details

  • 2P1-9 Design and visualization of ultrasonic wave in phononic structure for efficient energy transmission(Poster Session)

    Tsubouchi Kazuya, Ishikawa Atsushi, Fujimori Kazuhiro, Tsuruta Kenji

    Proceedings of Symposium on Ultrasonic Electronics   35   225 - 226   2014.12

     More details

    Language:English   Publisher:Steering committee of symposium on ultrasonic electronics  

    In this paper, we discussed the design of the ultrasonic WPT system, consisting of impedance-matched transducers, phononic-crystal structure, and the Schlieren optical measurement system. The transducers we designed show 60% energy-transmission efficiency at 1.2MHz. The phononic structure is designed via phonon-band analysis and fabricated by using 3D printer for controlling ultrasonic wave. The Schlieren optical measurement system is also designed for analyzing actual wave propagation in water at MHz regime without disturbing the wave propagation.

    CiNii Article

    CiNii Books

    researchmap

  • Acoustic Wave on Piezoelectric Semiconductor Film via Large-scale Molecular Dynamics Analysis

    Hikata Ryo, Tsuruta Kenji, Ishikawa Atsushi

    The Computational Mechanics Conference   2014 ( 27 )   318 - 319   2014.11

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • Terahertz Wave Response of Graphene Periodic Structure using FDTD Method

    Yatooshi Takumi, Ishikawa Atsushi, Tsuruta Kenji

    The Computational Mechanics Conference   2014 ( 27 )   323 - 324   2014.11

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 酸素ポテンシャル勾配下におけるアルミナ粒界拡散に関する理論解析

    小川貴史, 桑原彰秀, CRAIG Fisher, 森分博紀, 北岡諭, 松永克志, 鶴田健二

    日本金属学会講演概要(CD-ROM)   154th   2014

  • 2420 Effect of Dopant Segregation into Dislocation Core in Alumina : A Hybrid Quantum/Classical Molecular Dynamics

    Asano Tatsunao, Takata Kazuaki, Tsuruta Kenji, Fujimori Kazuhiro

    The Computational Mechanics Conference   2013 ( 26 )   "2420 - 1"-"2420-2"   2013.11

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 2414 Local Electronic States in CNT/GaAs Hetero Solar Cell :An Ab-initio Study

    ITAMI Masahiko, TSURUTA Kenji

    The Computational Mechanics Conference   2013 ( 26 )   "2414 - 1"-"2414-2"   2013.11

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 28pXZB-4 Effect of Dopant Segregation into Dislocation Core in Alumina : A Hybrid Quantum/Classical Molecular Dynamics Analysis

    Takata K., Tsuruta K., Fujimori K.

    Meeting abstracts of the Physical Society of Japan   68 ( 1 )   1045 - 1045   2013.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27aXK-5 First-principles Calculation of Electronic States in Carbon Nanotube/GaAs Interface : Carrier Transfer and Impurity Effects

    Itami M., Tsuruta K., Fujimori K., Fukano H.

    Meeting abstracts of the Physical Society of Japan   68 ( 1 )   985 - 985   2013.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • B-1-15 A Consideration about Influence of Capacitance of Diode under the State of Rectifying Operation at Microwave Frequency

    Taniguchi Mamoru, Wagi Teruhiko, Fujimori Kazuhiro, Tsuruta Kenji

    Proceedings of the IEICE General Conference   2013 ( 1 )   15 - 15   2013.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • B-1-26 A Fundamental Investigation of Operating Condition for Highly Efficient RF-DC Conversion Circuit by Using Genetic Algorithm

    Ota Kosuke, Kondo Yoshihiro, Fujimori Kazuhiro, Tsuruta Kenji

    Proceedings of the IEICE General Conference   2013 ( 1 )   26 - 26   2013.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 第一原理計算に基づくアルミナ粒界における空孔形成と拡散挙動の解析

    小川貴史, 桑原彰秀, FISHER Craig A. J., 森分博紀, 松永克志, 鶴田健二, 北岡諭

    日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)   26th   2013

  • 1602 Design of High-Efficiency/Wideband Transducer for Ultrasonic Wireless Power Transmission System

    TOMINAGA Shota, TANDA Koichiro, FUJIMORI Kazuhiro, TSURUTA Kenji, NOGI Sigeji

    The Computational Mechanics Conference   2012 ( 25 )   612 - 613   2012.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 2102 Large Scale Molecular Dynamics Analysis on Stability of Screw Dislocation in Alumina

    Takata Kazuaki, Tsuruta Kenji, Fujimori Kazuhiro

    The Computational Mechanics Conference   2012 ( 25 )   174 - 175   2012.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    Using large-scale molecular dynamics simulation, we investigate the stability of screw dislocation in α-alumina. Energies of perfect and partial screw dislocations in α-alumina crystal are compared at several temperatures. In the case of screw dislocation results reveal that perfect dislocation in alumina is more stable than partial dislocations. This result is consistent with the experimental observations in that the screw dislocation in alumina is stable against dissociation into partials. We also evaluate the temperature dependence of rigidity modulus of alumina from the stress-distribution calculations.

    CiNii Article

    CiNii Books

    researchmap

  • 2106 Hybrid MC/MD simulation of grain boundary segregation in semiconductor/ceramic materials

    SUGAHARA Kazuhito, TAKATA Kazuaki, TSURUTA Kenji, FUJIMORI Kazuhiro

    The Computational Mechanics Conference   2012 ( 25 )   182 - 183   2012.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    We demonstrate the effectiveness of a hybrid Monte Carlo (MC)/molecular dynamics (MD) method in analysis of grain-boundary segregation, a long-time phenomenon from the atomistic-simulation point of view. The Σ9 coincidence grain boundary of Si crystal is adopted as a testbed for the method. We find an efficient sampling of hopping diffusion of a vacancy in the system can be achieved, while the internal energy evaluated from the MD runs at the same temperature as the MC simulation includes the structural relaxation of the system at the temperature.

    CiNii Article

    CiNii Books

    researchmap

  • 2113 Electronic states and transport properties in carbon nanotube/GaAs interface using first-principles calculation

    ITAMI Masahiko, TSURUTA Kenji, Fujimori Kazuhiro

    The Computational Mechanics Conference   2012 ( 25 )   198 - 199   2012.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • B-9-2 Comparison of the conversion efficiency in a series type and a shunt type RF-DC conversion circuit

    Ota Kosuke, Wagi Teruhiko, Fujimori Kazuhiro, Tsuruta Kenji

    Proceedings of the IEICE General Conference   2012 ( 2 )   312 - 312   2012.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • CS-6-5 An Automatic Design for The RF-DC Conversion Circuit by using Genetic Algorithm

    Kondo Yoshihiro, Fujimori Kazuhiro, Tsuruta Kenji

    Proceedings of the IEICE General Conference   2012 ( 1 )   "S - 23"-"S-24"   2012.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • BCS-1-1 Characteristics of a RF-DC Conversion Circuit using a GaN Diode for Microwave Rectification

    WAGI Teruhiko, TAMARU Shoichi, FUJIMORI Kazuhiro, TSURUTA Kenji, NOGI Shigeji, OZAWA Yuichiro, FURUKAWA Minoru, FUJIWARA Teruo

    Proceedings of the IEICE General Conference   2012 ( 1 )   "S - 57"-"S-58"   2012.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • C-11-1 Structure and Electronic State on Dislocations in 4H-SiC : Tight-binding and First-principles Simulations

    Morisada Tomofumi, Hamasaki Fusanori, Tsuruta Kenji

    Proceedings of the IEICE General Conference   2012 ( 2 )   70 - 70   2012.3

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • The Conversion efficiency analysis of a shunt form RF-DC conversion circuit with the equivalent circuit parameter of a diode

    WAGI Teruhiko, TAMARU Shoichi, KONDO Yoshihoiro, FUJIMORI Kazuhiro, TSURUTA Kenji

    111 ( 412 )   201 - 206   2012.1

     More details

    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    The device called Rectenna as an antenna for Receive Antenna of radio electric power transmission is used. The RF-DC conversion circuit of high conversion efficiency which is a component of Rectenna cause wireless power transimission of high transmission efficiency. In this paper, The conversion efficiency analysis of RF-DC conversion circuit in change of component oh the diode are investigated to clarify the characteristic of the diode for obtaining highly efficiency conversion circuit.

    CiNii Article

    CiNii Books

    researchmap

  • Phononic-crystal acoustic lens by design for energy-transmission devices

    Yusuke Kanno, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    IEEJ Transactions on Electronics, Information and Systems   132 ( 5 )   686 - 690   2012

     More details

    Language:English   Publisher:Institute of Electrical Engineers of Japan  

    Lens effect of acoustic wave in two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal/ceramic cylinders placed periodically in water. Lens effect is observed for far-field wave in the phononic crystals with two-layered and graded-index structure. We compare the focal intensity and the energy transmission efficiency in these numerical experiments, and show that a novel energy-transmission device can be designed using phononic crystals. © 2012 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.132.686

    Scopus

    researchmap

  • 超音波無線電力伝送のための高効率なトランスデューサの設計と開発

    堀 祐貴, 藤森和博, 鶴田健二, 野木茂次

    電気学会論文誌C   132 ( 3 )   337 - 343   2012

  • Design and Development of Highly Efficient Transducer for Ultrasonic Wireless Power Transmission System

    Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    IEEJ Trans. Electronics, Information and Systems   132 ( 3 )   337 - 343   2012

  • Optically-powered voltage-supply-device for effective utilization of optical energy in the fiber-to-the-home network

    Hideki Fukano, Takeshi Shinagawa, Kenji Tsuruta

    IEEJ Transactions on Electronics, Information and Systems   132 ( 4 )   495 - 499   2012

     More details

    Language:English   Publisher:Institute of Electrical Engineers of Japan  

    An optically powered device with using InGaAs-Photodiode has been developed. This study aims to harvest light energy (2.8∼500 μW) from the FTTH (Fiber To The Home) network and to utilize it for operating remote sensors without external energy sources. First, we designed and evaluated the characteristics of the booster circuit and confirmed that it could boost an input voltage of 0.3 V to 3.0 V. Next, we also evaluated the characteristics of InGaAs photodiode and confirmed that it can output a voltage over 0.3 V at 10-μW input light. We demonstrate that a ready-made sensor can be operated with an input optical power as low as 10 μW. © 2012 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.132.495

    Scopus

    researchmap

  • Optically-powered voltage-supply-device for effective utilization of optical energy in the fiber-to-the-home network

    Hideki Fukano, Takeshi Shinagawa, Kenji Tsuruta

    IEEJ Transactions on Electronics, Information and Systems   132 ( 4 )   495 - 499   2012

     More details

    Language:English   Publisher:Institute of Electrical Engineers of Japan  

    An optically powered device with using InGaAs-Photodiode has been developed. This study aims to harvest light energy (2.8∼500 μW) from the FTTH (Fiber To The Home) network and to utilize it for operating remote sensors without external energy sources. First, we designed and evaluated the characteristics of the booster circuit and confirmed that it could boost an input voltage of 0.3 V to 3.0 V. Next, we also evaluated the characteristics of InGaAs photodiode and confirmed that it can output a voltage over 0.3 V at 10-μW input light. We demonstrate that a ready-made sensor can be operated with an input optical power as low as 10 μW. © 2012 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.132.495

    Scopus

    researchmap

  • 機能元素解析のための大規模有限温度分子動力学シミュレーション

    セラミックス   47 ( 7 )   489 - 493   2012

     More details

  • Large-scale Molecular Dynamics on Screw Dislocation in Alumina

    Kazuaki Takata, Akihiro Hayashi, Kenji Tsuruta

    AMTC Letters   3   132 - 133   2012

     More details

  • 1502 Ab Initio Simulation for Structure and Optical Response of Gemini-HBC

    Shimizu Tatsuki, Tsuruta Kenji, Fukano Hideki

    The Computational Mechanics Conference   2011 ( 24 )   471 - 473   2011.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    A graphite nanotube is composed of Gemini type hexabenzocoronene (Gemini-HBC) as the hole-transport layer and the fullerene as the electron-transport layer. We study the doping effect on the electronic properties of Gemini-HBC to make the absorption peak broader, expecting to cover an unharvested energy resource. Here we assume that structure of doped Gemini-HBC is well represented by substituting dopant atom to one of carbon sites. Calculations of the energy and absorption spectrum are performed by the ab-initio computational method. As a result, the absorption peak of the Gemini-HBC is about 0.5μm, whereas the first and second peaks for doped Gemini-HBC are also approximately 0.5μm. In addition, the absorption spectrum of F-doped Gemini-HBC has an additional peak around 0.95μm, implying the sunlight with the longer wavelength may be absorbed.

    CiNii Article

    CiNii Books

    researchmap

  • 1508 Diffusion barrier of Li in carbon-based anode material in Li-ion secondary battery via ab-initio and hybrid quantum/classical molecular-dynamics method

    INAGAKI Yosuke, TSURUTA Kenji

    The Computational Mechanics Conference   2011 ( 24 )   485 - 486   2011.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    Lithium ion battery (LiB) is widely used in portable electronic devices, such as cellular phones and laptop computers. Recently, needs for higher efficiency of the battery has been increasing rapidly due to the demand for electric and hybrid electric vehicle. At present, anode of LiB is mainly made of graphite. Recently, graphene has been attracting more attention as an alternative anode material. The effect of impurity doping to graphene has also been investigated recently. To optimize the materials combination for the anode applications microscopic mechanisms of such enhancement of electric capacity in LiB have to be identified. Using an ab-initio computational method, based on the density-functional theory, and its hybridized method with the classical molecular dynamics, we investigate dynamical behavior, such as diffusion processes, of Li atom in the carbon based materials with pristine, defected, and doped graphene.

    CiNii Article

    CiNii Books

    researchmap

  • 1503 Large Scale Molecular Dynamics Analysis on Vacancy Interaction in Si Crystal

    TAKATA Kazuaki, TSURUTA Kenji

    The Computational Mechanics Conference   2011 ( 24 )   474 - 475   2011.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    Vacancy interaction in Si crystal is studied by molecular-dynamics simulations. Using tight-binding molecular dynamics and classical molecular dynamics methods, we calculate an effective interaction potential of Si vacancy pair in bulk and in a thin slab at several temperatures. In the case of vacancy pair in bulk crystal, results reveal that there is an effective "capture radius" of the vacancies at around 8 Åat 300K and 13 Å at 600K and 1000K. Stable structure and electronic states around the vacancies in Si slab near the surface are qualitatively different from their bulk properties, reflecting a proximity surface electronic state. Results of diffusion behavior and interaction potential of the vacancy pair in the slab at finite temperatures are also reported.

    CiNii Article

    CiNii Books

    researchmap

  • 22aGQ-10 Molecular Dynamics Analysis on Vacancy Interaction near Surface and Interface in Si Crystal

    Takata K., Tsuruta K., Ogawa T., Iyetomi H.

    Meeting abstracts of the Physical Society of Japan   66 ( 2 )   981 - 981   2011.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27pTJ-10 Analyses on spin-orbit coupling effects of a silicon single vacancy via DFT calculations

    Ogawa Takafumi, Tsuruta Kenji, Iyetomi Hiroshi, Nemoto Yuichi, Yamada-Kaneta Hiroshi, Goto Terutaka

    Meeting abstracts of the Physical Society of Japan   66 ( 1 )   979 - 979   2011.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26aWZ-12 Analyses localized electron orbitals around a silicon single vacallcy via DFT calculations

    Ogawa Takafumi, Tsuruta Kenji, Iyetomi Hiroshi, Nemoto Yuichi, Yamada-Kaneta Hiroshi, Goto Terutaka

    Meeting abstracts of the Physical Society of Japan   65 ( 2 )   928 - 928   2010.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 20aHT-10 Multiscale Analysis on Impurity Segregation to Dislocation in Alumina

    Tsuruta K., Koyama T., Ogata S., Hyodo S.

    Meeting abstracts of the Physical Society of Japan   65 ( 1 )   971 - 971   2010.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Parallel FDTD simulations on optical and acoustic metamaterials

    Kenji Tsuruta, Shinji Nagai, Ryosuke Umeda, Tomoyuki Kurose, Noriaki Maetani

    Materials Research Society Symposium Proceedings   1223   1223-EE06   2010

     More details

  • Ab Initio Simulation for Structure and Optical Response of Gemini-HBC

    Tatsuki Shimizu, Kenji Tsuruta

    447 - 450   2010

     More details

  • 108 Hybrid Quantum/Classical Molecular-Dynamics Study on Dislocation Motion and Nanodopant Effects in Alumina

    TSURUTA Kenji, HAYASHI Akihiro, KOYAMA Toshiyuki, OGATA Shuji, HYODO Shiaki

    The Computational Mechanics Conference   2009 ( 22 )   390 - 391   2009.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    We perform molecular-dynamics simulations to investigate the atomic and electronic structures of a basal edge dislocation in α-Al_2O_3. Inter-core interactions between a dissociated partial pair are evaluated by a million-atom classical molecular dynamics. The interactions consists of a short-ranged repulsion due to the elastic interaction between two singular points and a long-ranged attraction due to the stacking-fault formed between the two partials. The atomic rearrangements in the full and in the partial dislocation cores are analyzed by a hybrid quantum/classical molecular dynamics method. The local electronic structure in the dislocation core is evaluated by the density-functional method applied for a quantum-cluster region in the hybrid simulation. Effects of a doped Si atom segregated to the dislocation core are also analyzed.

    CiNii Article

    CiNii Books

    researchmap

  • 1701 An FDTD Analysis of Light Confined Structure by Electromagnetic Metamaterials

    NAGAI Shinji, TSURUTA Kenji, TOTSUJI Chieko

    The Computational Mechanics Conference   2009 ( 22 )   452 - 453   2009.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    Using the two dimensional Finite Difference Time Domain method, we demonstrate a light-confinement phenomenon by a structure composed of a negative-refractive-indexed (NRI) material. The structure, consisting of triangular lattice of mediums with a NRI and a normal material, is designed to confine an incident light by peculiar refractions at the materials boundaries. To model realistically the NRI material, we introduce the Drude-Lorentz model for the dielectric response at optical frequencies. The effects of dielectric loss in the NRI medium on the confinement efficiency of the proposed structure is reported.

    CiNii Article

    CiNii Books

    researchmap

  • 1706 Numerical Simulation of Acoustic Wave in a Two-Dimensional Phononic Crystal : Negative Refraction and Lens Effect

    MAETANI Noriaki, TSURUTA Kenji, TOTSUJI Chieko

    The Computational Mechanics Conference   2009 ( 22 )   462 - 463   2009.10

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    Lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in acoustic waves refocused at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which reflects incident acoustic waves from the source. We show how the focal intensity is improved by using the 2D phononic crystal shield.

    CiNii Article

    CiNii Books

    researchmap

  • 25aPS-131 Analysis of Defect Orbital by Ab-initio Simulations and Elastic Softening in Silicon

    Ogawa T., Tsuruta K., Iyetomi H., Goto T., Yamada-Kaneta H.

    Meeting abstracts of the Physical Society of Japan   64 ( 2 )   446 - 446   2009.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27aRB-11 Strain field and elastic properties of vacancy in silicon : Classical and tight-binding molecular dynamics simulations

    Ogawa T., Tsuruta K., Iyetomi H., Goto T., Yamada-Kaneta H.

    Meeting abstracts of the Physical Society of Japan   64 ( 1 )   932 - 932   2009.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 30aSK-11 Transfer of quantum information and creation of entanglement by coupled spin chains

    Chai H., Totsuji H., Totsuji C., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   64 ( 1 )   182 - 182   2009.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multiscale Simulations for Atomic-scale Modification of Nanomaterials

    Kenji Tsuruta, Toshiyuki Koyama, Ryo Kobayashi, Shuji Ogata, Shiaki Hyodo

    Materia Japan   48 ( 6 )   303 - 306   2009

     More details

  • Multiscale Simulations for Atomic-scale Modification of Nanomaterials

    TSURUTA Kenji, KOYAMA Toshiyuki, KOBAYASHI Ryo, OGATA Shuji, HYODO Shiaki

    Bulletin of the Japan Institute of Metals   48 ( 6 )   303 - 306   2009

     More details

    Language:Japanese   Publisher:The Japan Institute of Metals and Materials  

    DOI: 10.2320/materia.48.303

    CiNii Article

    CiNii Books

    researchmap

    Other Link: https://jlc.jst.go.jp/DN/JALC/00333014217?from=CiNii

  • 22pRB-5 Analysis of Electron Systems by Classical Mapping : Wigner Crystallization of Two-Dimensional Electrons in a Finite Domain

    Miyake T., Totsuji C., Nakanishi K., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   63 ( 2 )   239 - 239   2008.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 20pZD-10 Transfer of quantum information and creation of entanglement by coupled spin chains

    Totsuji H., Chai H., Totsuji C., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   63 ( 2 )   106 - 106   2008.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 21pRB-5 Revisit to the Nature of an Isolated Vacancy in Silicon : Large-scale Density-functional Calculations

    Tsuruta Kenji

    Meeting abstracts of the Physical Society of Japan   63 ( 2 )   876 - 876   2008.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 21aRB-10 Revisit to the Ground State for a Single Vacancy in Crystal Silicon

    Ogawa T., Tsuruta K., Iyetomi H., Goto T., Kaneta H. Y.

    Meeting abstracts of the Physical Society of Japan   63 ( 2 )   868 - 868   2008.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 23aTE-6 CHNC simulations of 2D-electron fluid at finite temperatures

    Totsuji C., Nakanishi K., Miyake T., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   63 ( 1 )   260 - 260   2008.2

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 24pYF-6 Temperature dependence of elastic constants of Si crystal with vacancy : TBMD and DFT analyses

    Ogawa T., Tsuruta K., Iyetomi H, Goto T., Kaneta H., Totsuji C., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   63 ( 1 )   937 - 937   2008.2

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 22aWA-11 Analysis of Electron Systems by Classical Mapping : Spin Polarization of Two-Dimensional Electrons in a Finite Domain

    Miyake T., Nakanishi K., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   62 ( 2 )   284 - 284   2007.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 22pTD-10 Electronic States and Vibrational Modes of Atomic Vacancy in Si Crystal : Ab Initio and Tight-binding Calculations

    Tsuruta K., Ogawa T., Iyetomi H, Goto T., Kaneta H, Totsuji C., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   62 ( 2 )   994 - 994   2007.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 19pQE-16 Oscillation Spectrum in Spherical Coulomb and Yukawa Clusters

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   62 ( 1 )   210 - 210   2007.2

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 19pWB-10 Ground State of Two-Dimensional Electron Systems : Molecular Dynamics Simulation Based on Classical Mapping

    Nakanishi Kenta, Totsuji Chieko, Miyake Takashi, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   62 ( 1 )   269 - 269   2007.2

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multiscale molecular dynamics simulations of nanostructured materials

    Kenji Tsuruta, Atsushi Uchida, Chieko Totsuji, Hiroo Totsuji

    THERMEC 2006, PTS 1-5   539-543   2804 - +   2007

     More details

    Language:English   Publisher:TRANS TECH PUBLICATIONS LTD  

    We present some attempts to simulate nanoscale phenomena, which involve different length-scales and time-scales, using multiscale molecular-dynamics approaches. To simulate realistically an impurity-segregated nanostructure, we have developed the hybrid quantum/classical approach, The method can describe seamlessly both dynamical changes of local chemical bonding and nanoscale atomic relaxations. We apply the method to hydrogen diffusion in Si grain boundary. We find that the hydrogen is strongly trapped in (001)Sigma 5 twist boundary below 1000K, whereas it starts diffusing along the grain boundary above 1000K. For long-time processes in nanostructure formation, we apply the stochastic-difference-equation method to accelerate the simulations for microstructure evolution. The method bridges the states separated by high-energy barriers in a configuration space by optimizing an action, defined as an error accumulation along a reaction pathway. As an example, a SDE simulation is performed for Cu thin-film formation via nanocluster deposition. We show that the method can be applied effectively to search for the long-time process which involves a rare event due to a large potential barrier between two atomic configurations.

    Web of Science

    researchmap

  • Structure and melting of clusters of micron-sized particles in plasmas under microgravity : Numerical and theoretical studies

    OGAWA Takafumi, TOTSUJI Chieko, TSURUTA Kenji, TOTSUJI Hiroo

    23 ( 4 )   330 - 330   2006.11

     More details

  • 25aYB-7 TBMD Simulations of Carbon Nanotube/Ni Interfaces

    Tsuruta K., Srivastava Deepak, Totsuji C., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   61 ( 2 )   687 - 687   2006.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 25pYK-10 Hydrogen Diffusion in Si Crystal : Hybrid MD/TBMD Simulations

    Tsuruta K., Hamasaki I., Totsuji C., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   61 ( 2 )   806 - 806   2006.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26aQB-11 Particle Simulations of melting of Three-Dimensional Yukawa clusters

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   61 ( 2 )   168 - 168   2006.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 28aXH-11 Parameterization in the classical mapping method for quantum electron liquids

    Miyake Takashi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   61 ( 1 )   284 - 284   2006.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27aUC-8 Melting of dust particle clusters under microgravity analyzed by Monte Carlo Simulation

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   61 ( 1 )   195 - 195   2006.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Distribution of Electrons in Quantum Dots Analyzed by Classical Mapping and Molecular Dynamics

    Takashi Miyake, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Memoirs of the Faculty of Engineering, Okayama University   40 ( 1 )   40 - 43   2006.1

     More details

    Language:English   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • Melting of Spherical Yukawa Clusters Analyzed by Monte CarloSimulation

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Memoirs of the Faculty of Engineering, Okayama University   40 ( 1 )   31 - 35   2006.1

     More details

    Language:English   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • 21pWG-2 Structure of dust particle clusters under microgravity : Analysis based on shell model

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   60 ( 2 )   119 - 119   2005.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 22pXL-14 Analysis of two-dimensional finite electron liquids by classical mapping

    Miyake T., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   60 ( 2 )   216 - 216   2005.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Large-scale FDTD Simulations on Parallel Computers : An Application to Photonic-Crystal Devices

    HIRAHATA Yoshiaki, TSURUTA Kenji, TOTSUJI Chieko, TOTSUJI Hiroo, FUJIMORI Kazuhiro

    24   67 - 70   2005.7

     More details

  • A Consideration for Promotion of Streamlining for Property Analysis of Amplifier at Microwave Range by FDTD Method.

    KAWASHIMA Naoto, FUJIMORI Kazuhiro, TSURUTA Kenji, FUJIWARA Koji, NOGI Shigeji

    24   63 - 66   2005.7

     More details

  • 26pYF-13 Tight-binding approach to electronic dynamics in semiconducting nanostructuree

    Kadono K., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   60 ( 1 )   310 - 310   2005.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26pXG-7 Structure formation of dust particles under microgravity

    Ogawa Takafumi, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   60 ( 1 )   243 - 243   2005.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26pYM-1 TBMD and Hybrid MD/TBMD Simulations of Si Grain Boundaries : Locality of Electronic States and Hydrogen Diffusion

    Tsuruta K., Totsuji C., Totsuji H., Ogata S.

    Meeting abstracts of the Physical Society of Japan   60 ( 1 )   918 - 918   2005.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Large-Scale Molecular Dynamics Simulation of CoulombClusters: A Finite-Temperature Analysis

    Kanamori Katsuya, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Memoirs of the Faculty of Engineering, Okayama University   39 ( 1 )   52 - 55   2005.1

     More details

    Language:English   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • Toward Larger-Scale, More Accurate MD Simulations : On A Hybrid Quantum/Classical Approach

    TSURUTA Kenji

    Journal of the Japan Society of Mechanical Engineers   Vol.108, No. 1043 ( 1043 )   809 - 811   2005

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • Strategic Application of Asia-Pacific GRID for Ultrascale Materials Simulations

    NAKANO Aiichiro, KALIA Rajiv K., VASHISHTA Priya, OGATA Shuji, SEKIGUCHI Satoshi, TANAKA Yoshio, TSURUTA Kenji

    Journal of the Japan Society of Mechanical Engineers   Vol.108, No. 1043 ( 1043 )   815 - 817   2005

     More details

    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    CiNii Article

    CiNii Books

    researchmap

  • 28aWM-7 Electron Dynamics in Semiconductor Nanowires

    Kadono K., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   59 ( 1 )   286 - 286   2004.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Mechanisms of impury diffusion on Si with a point defect: Tight-binding molecular dynamics simulation

    Takahiro Igarashi, Hiroshi Iyetomi, Kenji Tsuruta, Shuji Ogata

    Transactions of Materials Reseach Society of Japan   2004

     More details

  • Tight-binding approach to electron transport in nanostructured semiconductor

    Keisuke Kadono, Kenji Tsuruta, Chieko Totsuji, Hiroo Totsuji

    Transactions of Materials Reseach Society of Japan   2004

     More details

  • Hydrogen diffusion in Si: A tight-binding molecular dynamics study

    Masataka Yokoyama, Chieko Totsuji, Kenji Tsuruta, Hiroo Totsuji

    Transactions of Materials Reseach Society of Japan   2004

     More details

  • Parallel TBMD and hybrid MD/TBMD simulations of nanostructured materials

    Kenji Tsuruta, Chieko Totsuji, Hiroo Totsuji, Shuji Ogata

    Transactions of Materials Reseach Society of Japan   2004

     More details

  • Dynamical Properties of Two-dimensional Dusty Plasmas : A Molecular Dynamics Study

    Liman M. S., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   58 ( 2 )   189 - 189   2003.8

     More details

    Language:English   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Thermodynamic Stability of Dusty Plasmas

    Totsuji H., Liman M. S., Totsuji C., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   58 ( 2 )   189 - 189   2003.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Formation and stability of grain boundaries of nanostructured Si and SiC : Parallel TBMD and hybrid MD/TBMD simulations

    Tsuruta K., Oka K., Totsuji C., Totsuji H., Ogata S.

    Meeting abstracts of the Physical Society of Japan   58 ( 2 )   855 - 855   2003.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Diffusion Mechanisms of Impurities and Point Defects in Silicon : Tight-Binding Molecular Dynamics Simulation

    Igarashi T., Iyetomi H., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   58 ( 2 )   856 - 856   2003.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Estimation of screening length and electric charge on particles in single-layered dusty plasma crystals

    Totsuji Chieko, Liman M. S., Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   58 ( 2 )   189 - 189   2003.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Molecular Dynamics Simulations of Wave Dispersion Relations in Two Dimensional Yukawa fluids

    Liman M. Sanusi, Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   58 ( 1 )   209 - 209   2003.3

     More details

    Language:English   Publisher:The Physical Society of Japan (JPS)  

    The dynamical form factor and the wave dispersion relations of the two-dimensional Yukawa fluids are obtained by extensive molecular dynamics simulations for a wide range of coupling and the screening parameters. It is observed that, for weak screening, the transverse wave dispersion has a cut-off at a long wavelength. The simulation results are compared with the earlier theoretical predictions of the Yukawa dispersion relations and good agreement is found in the regimes of interest.

    CiNii Article

    CiNii Books

    researchmap

  • セラミックス・ナノ微粒子系の原子論的シミュレーション

    鶴田健二

    粉砕   46号 (平成14年) 別冊,pp.33-36   2003

     More details

  • Stability of amorphous grain boundary of Si:MD/TBMD simulations

    Tsuruta K, Miyake T, Ueno H, Totsuji C, Totsuji H

    Meeting abstracts of the Physical Society of Japan   57 ( 2 )   832 - 832   2002.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27pXQ-2 Confined Yukawa System: Simulation and Theory of One- and Multi-Component Systems under Microgravity III

    Totsuji H., Totsuji C., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 )   218 - 218   2002.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27pXQ-3 Ground States and Structural Transition in Coulomb Clusters

    Totsuji C., Kishimoto T., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 )   218 - 218   2002.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 25aXR-10 Point Defects and Impurity in Silicon CrystalTight Binding Molecular Dynamics Simulation

    Igarashi T., Nomura K., Iyetomi H., Kohayashi M., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 )   893 - 893   2002.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Atomic Structure of Grain Boundaries in Diamond : A Tight-Binding Molecular Dynamics Study

    FURUBAYASHI T.

    Trans. MRS-J   27   305 - 308   2002

  • 原子論/電子論にもとづくナノ微粒子界面現象のシミュレーション

    鶴田健二

    粉体工学会誌   第39巻,第9号,pp.692-702   2002

     More details

  • Confined Yukawa System : Simulation and Theory of One- and Multi-Component Systems under Microgravity II

    Totsuji H., Totsuji C., Tsuruta K., Kishimoto T.

    Meeting abstracts of the Physical Society of Japan   56 ( 2 )   139 - 139   2001.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Madelung Energy of Coulomb Clusters II

    Totsuji Hiroo, Kishimoto Tokunari, Totsuji Chieko, Tsuruta Kenji

    Meeting abstracts of the Physical Society of Japan   56 ( 2 )   142 - 142   2001.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Large-Scale Parallel Molecular Dynamics : Toward Computer-Aided Control of Defects and Interfaces in Materials

    Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   56 ( 2 )   798 - 798   2001.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Tight-Binding Molecular Dynamics Simulation of Impurity Diffusion in Nano-Structured Si

    Igarashi T., Nomura K., Iyetomi H., Kobayashi M., Tsuruta K.

    Meeting abstracts of the Physical Society of Japan   56 ( 2 )   788 - 788   2001.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Sintering and Dielectric Structures of TiO_2 Nanoparticles : Varible-Charge Molecular Dynamics

    Ogata S., Iyetomi H., Tsuruta K., Shimojo F.

    Meeting abstracts of the Physical Society of Japan   56 ( 2 )   788 - 788   2001.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Molecular Dynamics of Yukawa System using the Fast Multipole Method

    Kishimoto Tokunari, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Memoirs of the Faculty of Engineering, Okayama University   35 ( 1 )   77 - 95   2001.3

     More details

    Language:English   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • Sintering Simulation of Nanophase Ceramic by Constant-Pressure Tight-Binding Molecular Dynamics

    Tsuruta K., Totsuji H., Totsuji C.

    Meeting abstracts of the Physical Society of Japan   56 ( 1 )   874 - 874   2001.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Detailed Dynamical Analyses on Sintering Processes of TiO_2 Nanoparticles : Variable-Charge Molecular Dynamics Simulations

    Iyetomi Hiroshi, Ogata Shuji, Tsuruta Kenji, Shimojo Fuyuki

    Meeting abstracts of the Physical Society of Japan   56 ( 1 )   846 - 846   2001.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Quantum Simulation of Hydrogen Plasma : Dynamic Properties

    Totsuji H., Nishii Y., Totsuji C., Tsuruta K., Fukumoto I., Chihara J., Yamagiwa M., Tajima T.

    Meeting abstracts of the Physical Society of Japan   56 ( 1 )   179 - 179   2001.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Madelung Energy of Coulomb Clusters

    Kishimoto Tokunari, Totsuji Chieko, Tsuruta Kenji, Totsuji Hiroo

    Meeting abstracts of the Physical Society of Japan   56 ( 1 )   204 - 204   2001.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • ナノ材料シミュレーションの最近の展開

    家富洋, 尾形修司, 菊池英明, 下條冬樹, 鶴田健二, 中野愛一郎, R. K. Kalia, P. Vashishta

    マテリアルインテグレーション   Vol. 14 No. 1, pp.3-8   2001

     More details

  • Parallel Molecular Dynamics of Coulomb Clusters

    T. Kishimoto, C. Totsuji, K. Tsuruta, H. Totsuji

    Proceedings of the International Congress on Plasma Physics 2000   2001

     More details

  • Sintering of TiO2 Nanoparticles: Variable-Charge Molecular Dynamics on PC clusters

    Shuji Ogata, Hiroshi Iyetomi, Kenji Tsuruta, Fuyuki Shimojo

    International Simposia on Materials Science for the 21st Century   2001

     More details

  • Structures of Confined Yukawa System with and without Gravity

    C. Totsuji, T. Kishimoto, K. Tsuruta, H. Totsuji

    Proceedings of the International Congress on Plasma Physics 2000   2001

     More details

  • Initial stages of sintering of TiO2 nanoparticles: Variable-charge molecular dynamics simulations

    S. Ogata, H. Iyetomi, K. Tsuruta, F. Shimojo, A. Nakano, P. Vashishta, R. K. Kalia, C.-K. Loong

    Mat. Res. Soc. Symp. Proc.   2001

     More details

  • Parallel Tight-Binding Simulations of Nanophase Ceramics: Atomic and Electronic Transport at Grain Boundaries

    K. Tsuruta, H. Totsuji, C. Totsuji

    Mat. Res. Soc. Symp. Proc.   2001

     More details

  • Confined Yukawa System: Simulation and Theory of One- and Multi- Component Systems under Microgravity

    Totsuji H., Kishimoto T., Tsuruta K., Totsuji C.

    Meeting abstracts of the Physical Society of Japan   55 ( 2 )   190 - 190   2000.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Variable-Charge Molecular Dynamics Simulations for Structure and Space Charge Distribution in Nanophased TiO_2

    Iyetomi Hiroshi, Ogata Shuji, Tsuruta Kenji, Simojo Fuyuki

    Meeting abstracts of the Physical Society of Japan   55 ( 2 )   860 - 860   2000.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Sintering Simulations of SiC Nanocrystals via Tight-binding Molecular Dynamics

    Tsuruta K., Totsuji H., Totsui C.

    Meeting abstracts of the Physical Society of Japan   55 ( 2 )   859 - 859   2000.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Quantum Molecular-Dynamics Simulation of Hydrogen Plasma : Parallelization Strategies and Performance

    Tsuruta K., Ueshima Y., Chihara J., Tajima T., Nishii Y., Totsuji C., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   129 - 129   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Quantum Simulation of Hydorgen Plasma : Thermodynamic Properties

    Nishii Y., Totsuji C., Tsuruta K., Totsuji H., Ueshima Y., Chihara J., Tajima T.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   129 - 129   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Structure and Melting of Two-Dimensional Dust Crystals (2)

    Kamon K., Kishimoto T., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   153 - 153   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multicomponent Plasmas in Penning Traps : Parallel Molecular Dynamics of 10^5 ions on PC Cluster

    Kishimoto T., Nakano K., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   152 - 152   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multicomponent Plasmas in Penning Trap : Relaxation in Strong Magnetic Field

    Totsuji H., Kishimoto T., Tsuruta K., Totsuji C.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   152 - 152   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Analysis of Si/Ge via Nonorthogonal Tight-Binding Method

    Shinomiya S., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   857 - 857   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Simulation on Aggregation of TiO_2 Nano-Particulates : Effects of Surface Charge Layer

    Iyetomi Hiroshi, Ogata Shuji, Tsuruta Kenji, Shimojo Fuyuki, Kalia Rajiv K., Nakano Aiichiro, Vashishta Priya

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   864 - 864   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Tight-binding Molecular Dynamics of SiC : Sintering of Nanocrystals and Extraction Schemes for TB Parameters

    Tsuruta K., Totsuji H., Totsuji C., Kohyama M.

    Meeting abstracts of the Physical Society of Japan   55 ( 1 )   865 - 865   2000.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Tight-binding molecular dynamics of ceramic nanocrystals using PC-based parallel machines

    K Tsuruta, H Totsuji, C Totsuji

    NANOPHASE AND NANOCOMPOSITE MATERIALS III   581   673 - 678   2000

     More details

    Language:English   Publisher:MATERIALS RESEARCH SOCIETY  

    Evolution of atomic and electronic structures of silicon-carbide (SiC) nanocrystals during sintering is investigated by a tight-binding molecular dynamics (TBMD) method. An O(N) algorithm (the Fermi-operator expansion method) is employed for calculating electronic contributions in the energy and forces. Simulations are performed on our eight-node parallel PC cluster. In a sintering simulation of aligned (no tilt or twist) SiC nanocrystals at T=1000K we find that a neck is formed promptly without formation of defects. Analyses of local electronic density-of-states (DOS) and effective charges reveal that unsaturated bonds exist only in grain surfaces accompanying the gap states. In the case of tilted (&lt;122&gt;) nanocrystals, surface structures formed before sintering affect significantly the grain-boundary formation.

    Web of Science

    researchmap

  • Variable-charge molecular dynamics of aggregation of TiO2 nanocrystals

    S Ogata, H Iyetomi, K Tsuruta, F Shimojo, A Nakano, RK Kalia, P Vashishta

    GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES   118   79 - 86   2000

     More details

    Language:English   Publisher:AMER CERAMIC SOC  

    Molecular dynamics (MD) simulations of both rutile and anatase TiO2-nanoclusters (size 60-80 Angstrom) are performed using an environment-dependent interatomic potential developed recently by Ogata et al. [J. Appl. Phys. 86 [16], 3036-3041 (1999)]. In the potential, atomic charges vary dynamically according to the generalized electronegativity-equalization principle. Formation of double-charge layer and enhanced atomic diffusion are observed in surface regions of the free TiO2-nanospheres by inclusion of the atomic-charge variation. Their effects on aggregation processes of TiO2 nanoclusters are investigated through MD simulations.

    Web of Science

    researchmap

  • Tight-binding molecular dynamics of ceramic nanocrystals using parallel PC cluster

    K Tsuruta, H Totsuji, C Totsuji

    GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES   118   33 - 39   2000

     More details

    Language:English   Publisher:AMER CERAMIC SOC  

    Tight-binding molecular dynamics (TBMD) simulations are performed to study atomistic/electronic structures and electronic transport in nanocrystalline silicon-carbide ceramic (nc-SiC). The simulations are based on an O(N) algorithm (the Fermi-operator expansion method) for calculating electronic contributions in the energy and forces. The code has been fully parallelized on our Pentium-based parallel machines.
    In a sintering simulation of aligned (no tilt or twist) SiC nanocrystals at T approximate to 730 degreesC, we find that a neck is formed promptly without formation of defects. Analyses reveal that unsaturated bonds exist only in grain surfaces accompanying the gap states. In the case of tilted (&lt; 122 &gt;) nanocrystals, surface structures formed before sintering affect significantly the grain-boundary formation. An electrical conductivity of the sintered (aligned) nc-SiC system is estimated via the Kubo-Greenwood formula with tight-binding representation. Effects of surface states on the conductivity is analyzed.

    Web of Science

    researchmap

  • Intercluster interaction of TiO2 nanoclusters using variable-charge interatomic potentials

    S Ogata, H Iyetomi, K Tsuruta, F Shimojo, RK Kalia, A Nakano, P Vashishta

    NANOPHASE AND NANOCOMPOSITE MATERIALS III   581   667 - 672   2000

     More details

    Language:English   Publisher:MATERIALS RESEARCH SOCIETY  

    A new interatomic potential has been developed for molecular-dynamics simulations of TiO2 based on the formalism of Streitz and Mintmire [J. Adhesion Sci. Technol. 8, 853 (1994)], in which atomic charges vary dynamically according to the generalized electronegativity-equalization principle. The present potential reproduces various quantities of rutile crystal including vibrational density of states, static dielectric constants, melting temperature, elastic moduli, and surface relaxation. Calculated cohesive-energy and dielectric constants for anatase crystal agree well with experimental data The potential is applied to TiO2 nanoclusters (size 60-80 Angstrom) for both anatase and rutile phases to analyze their equilibrium configuration and space-charge distribution. Stable double-charge layer is found in the surface region of a spherical nanocluster for both rutile and anatase, resulting in enhanced Coulomb-repulsion between the nanoclusters at close proximity.

    Web of Science

    researchmap

  • 25aYL-8 Tight-binding Molecular Dynamics of Sintering of Ceramic Nanocrystals

    Tsuruta K, Totsuji H, totsuji C

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   884 - 884   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 25aYL-9 Variable-Charge Molecular Dynamics Simulations of Sintering of TiO_2 Nano-particulates

    Iyetomi Hiroshi, Ogata Shuji, Tsuruta Kenji, Shimojo Fuyuki, Kalia Rajiv K., Nakano Aiichiro, Vashishta Priya

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   884 - 884   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26pYN-2 Structure of Two-Dimensional Dust Crystal : Theoretical Analysis

    Totsuji H, Totsuji C, Tsuruta K, Kamon K

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   177 - 177   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26pYN-1 Structure and Melting of Two-Dimensional Dust Crystal : Molecular Dynamics Simulation

    Totsuji H, Kamon K, Totsuji C, Tsuruta K

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   177 - 177   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26pYN-7 Melecular Dynamics of Quantum Plasma III

    Totsuji H, Tsuruta K, Totsuji C, Nishii Y, Kishimoto T

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   178 - 178   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 26aYN-1 Relaxation Process of Multicomponent Plasmas in Penning Traps

    Kishimoto T, Nakano K, Totsuji C, Tsuruta K, Totsuji H

    Meeting abstracts of the Physical Society of Japan   54 ( 2 )   168 - 168   1999.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multicomponent Plasmas in Penning-Malmberg Traps

    Totsuji Hiroo, Tsuruta Kenji, Totsuji Chieko

    Memoirs of the Faculty of Engineering, Okayama University   33 ( 2 )   61 - 69   1999.4

     More details

    Language:English   Publisher:Faculty of Engineering, Okayama University  

    CiNii Article

    CiNii Books

    researchmap

  • 31a-XM-11 Multicomponent Plasmas in Penning Traps : Theory and Simulation

    Nakano K., Kamon K., Sasabe T., Kishimoto T., Totsuji C., Tsuruta K., Totsuji H.

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   835 - 835   1999.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 31a-XM-12 Molecular Dynamics of Quantum Plasmas II

    Totsuji K., Tsuruta K., Totsuji C., Kishimoto T., Sasabe T.

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   835 - 835   1999.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 28a-ZA-8 Interfaces of Ceramics and Semiconductors via O(N) TBMD Simulations

    Tsuruta K., Totsuji H., Totsuji C., Shinomiya S.

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   100 - 100   1999.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 29a-ZA-7 Variable-charge potentials for molecular-dynamics simulations of TiO_2

    Ogata S., Iyetomi H., Tsuruta K., Shimojou F., Nakano A., Kalia R.K., Vashishta P.

    Meeting abstracts of the Physical Society of Japan   54 ( 1 )   106 - 106   1999.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Atomistic simulation of nanostructured materials

    A Nakano, ME Bachlechner, TJ Campbell, RK Kalla, A Omeltchenko, K Tsuruta, P Vashishta, S Ogata, Ebbsjo, I, A Madhukar

    IEEE COMPUTATIONAL SCIENCE & ENGINEERING   5 ( 4 )   68 - 78   1998.10

     More details

    Language:English   Publisher:IEEE COMPUTER SOC  

    Materials and devices with microstructures on the nanometer scale are revolutionizing technology, but until recently simulation at this scale has bean problematic. Developments in parallel computing are now allowing atomistic simulation using multiresolution algorithms, such as fast multipole methods. With these algorithms, researchers may soon be able to simulate applications up to one billion atoms.

    DOI: 10.1109/99.735897

    Web of Science

    researchmap

  • Internal structure of oxidized Al nanocluster obtained through variable-charge molecular dynamics

    OGATA Shuji, TSURUTA K., CAMPBELL T.J, NAKANO A., KALIA R., VASHISHTA P.

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   121 - 121   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Phase Transition of Confined Yukawa System(Dusty Plasma)

    KISHIMOTO T., SASABE T., TOTSUJI C., TSURUTA K., TOTSUJI H.

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   932 - 932   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Multicomponent Plasmas in Penning Traps : Theory

    TOTSUJI Hiroo, TSURUTA Kenji, TOTSUJI Chieko

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   932 - 932   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Molecular Dynamics of Quantum Plasma

    TOTSUJI Hiroo, TSURUTA Kenji, TOTSUJI Chieko, KISHIMOTO Tokunari

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   932 - 932   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Sintering and Fracture in Nanophase Ceramics : Parallel Molecular-dynamics Study

    TSURUTA K., CHATTERJEE A., KIKUCHI H., OMELTCHENKO A., NAKANO A., KALIA R.K, VASHISHTA P.

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   122 - 122   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • Variable-Charge Molecular Dynamics Simulation on Grain Boundaries of TiO_2

    IYETOMI Hiroshi, OGATA Shuji, TSURUTA Kenji, CAMPBELL Timothy J, NAKANO Aiichiro, KALIA Rajiv K, VASHISHTA Priya

    Meeting abstracts of the Physical Society of Japan   53 ( 2 )   122 - 122   1998.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • SHORT-RANGE SCREENING POTENTIALS FOR CLASSICAL COULOMB FLUIDS - MONTE-CARLO SAMPLING AND CLUSTER MODEL STUDIES (VOL 50, PG 2977, 1994)

    S ICHIMARU, S OGATA, K TSURUTA

    PHYSICAL REVIEW E   51 ( 4 )   3788 - 3788   1995.4

     More details

    Language:English   Publisher:AMERICAN PHYSICAL SOC  

    Web of Science

    researchmap

  • 4a-YC-2 Dense Coulomb Matter : Cluster-Aggregation Model with Intercluster Interaction

    Tsuruta K, Ichimaru S

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1994 ( 3 )   203 - 203   1994.8

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 31a-YG-10 Cluster Aggregation Model of Dense Coulomb Matter

    Tsuruta K., Ichimaru S.

    Abstracts of the meeting of the Physical Society of Japan. Annual meeting   49 ( 3 )   273 - 273   1994.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 12a-A-11 Monte Carlo Cluster Model of Dense Coulomb Matter

    Tsuruta K., Ichimaru S.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1993 ( 3 )   245 - 245   1993.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 13p-M-7 Thermal Stability and Equation of State for Coulomb Clusters

    Tsuruta K., Ichimaru S.

    Abstracts of the meeting of the Physical Society of Japan. Sectional meeting   1993 ( 4 )   223 - 223   1993.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • BINDING-ENERGY, MICROSTRUCTURE, AND SHELL-MODEL OF COULOMB CLUSTERS

    K TSURUTA, S ICHIMARU

    PHYSICAL REVIEW A   48 ( 2 )   1339 - 1344   1993.8

     More details

    Language:English   Publisher:AMERICAN PHYSICAL SOC  

    By computer-simulation and analytic studies for binding energies and microscopic shell structures, it is shown that Coulomb clusters assume particularly stable configurations at certain ''magic numbers'' of particles. Through analyses with the spherical Voronoi numbers, a special role that the icosahedral geometry plays in shaping the particle configurations on the spherical surfaces is elucidated. Gross features in the cluster structures, such as the shell radii and intershell partition of particles, are well accounted for by an appropriate shell model.

    DOI: 10.1103/PhysRevA.48.1339

    Web of Science

    researchmap

  • 25p-C-2 Thermal and Dyamic Properties of Coulomb Clusters

    Tsuruta K, Ichimaru S

    1992 ( 4 )   135 - 135   1992.9

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 27p-Z-7 Binding Energies and Microstructures in Mesoscopic Systems of Charged Particles

    Tsuruta K, Ichimaru S

    47 ( 4 )   153 - 153   1992.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

  • 24a-D-2 Odering Processes in Trapped Ions

    Tsuruta K., Ichimaru S.

    1991 ( 4 )   108 - 108   1991.3

     More details

    Language:Japanese   Publisher:The Physical Society of Japan (JPS)  

    CiNii Article

    CiNii Books

    researchmap

▼display all

Presentations

  • First-principles analysis of stearic acid adsorption on calcite (104) surface International conference

    Narumi MACHIDA, Masaaki MISAWA, Y. KEZUKA, and Kenji TSURUTA

    The 9th International Symposium on Surface Science  2021.11.30  The Japan Society of Vacuum and Surface Science

     More details

    Event date: 2021.11.29 - 2021.12.1

    Language:English   Presentation type:Poster presentation  

    Venue:Takamatsu (Online)   Country:Japan  

  • Improvement of Variational Auto-Encoder Design of Organic Molecules by Discriminator

    Kyosuke SATO, Masaaki MISAWA, and Kenji TSURUTA

    Chem-Bio Informatics Society(CBI) Annual Meeting 2021  Chem-Bio Informatics Society

     More details

    Event date: 2021.10.26 - 2021.10.28

    Language:Japanese   Presentation type:Poster presentation  

    Venue:Online   Country:Japan  

  • Design of topological phononic structure for multi mode propagation International conference

    Hiroaki Takeshita , Masaaki Misawa , Kenji Tsuruta

    The 42nd Symposium on Ultrasonic Electronics  2021.10.27  Comittee of Symposium on Ultraonics Electronics

     More details

    Event date: 2021.10.25 - 2021.10.27

    Language:English   Presentation type:Poster presentation  

    Venue:Online   Country:Japan  

  • Design of High-efficiency Sound Absorption and Energy Harvesting Devices Using Acoustic Metasurfaces International conference

    Ryota Takami , Masaaki Misawa , Kenji Tsuruta

    The 42nd Symposium on Ultrasonic Electronics  2021.10.27  Comittee of Symposium on Ultraonics Electronics

     More details

    Event date: 2021.10.25 - 2021.10.27

    Language:English   Presentation type:Poster presentation  

    Venue:Online   Country:Japan  

  • Band Structure Design for a Two-Dimensional Phononic Crystal using Various Optimization Methods International conference

    Kazuki Akae, Masaaki Misawa, Kenji Tsuruta

    The 42nd Symposium on Ultrasonic Electronics  2021.10.26  Comittee of Symposium on Ultraonics Electronics

     More details

    Event date: 2021.10.25 - 2021.10.27

    Language:English   Presentation type:Poster presentation  

    Venue:Online   Country:Japan  

  • Design and measurement of topological elastic waveguide based on phononic crystal International conference

    Motoki Kataoka, Masaaki Misawa, Kenji Tsuruta

    The 42nd Symposium on Ultrasonic Electronics  2021.10.25  Comittee of Symposium on Ultraonics Electronics

     More details

    Event date: 2021.10.25 - 2021.10.27

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Online   Country:Japan  

  • リザバーコンピューティングを用いたデジタルメタマテリアルの光学応答予測

    目黒智也, 佐藤郷介, 三澤賢明, 藤森和博, 鶴田健二

    2021年度(第72回)電気・情報関連学会 中国支部連合大会  2021.10.23  映像情報メディア学会・電気設備学会・照明学会 電子情報通信学会・電気学会・情報処理学会 中国支部

     More details

    Event date: 2021.10.23

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:広島工大(オンライン)   Country:Japan  

  • バンド構造を最適化する2次元フォノニック結晶の構造探 索

    赤江 一樹,三澤 賢明,鶴田 健二

    第 34 回計算力学講演会  2021.9.21  日本機械学会

     More details

    Event date: 2021.9.21 - 2021.9.23

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  • 高効率弾性波輸送のためのトポロジカルフォノニック構 造設計

    片岡 源樹,竹下 弘明,三澤 賢明,鶴田 健二

    第 34 回計算力学講演会  2021.9.21  日本機械学会

     More details

    Event date: 2021.9.21 - 2021.9.23

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  • カルサイト(104)表面におけるステアリン酸の吸着に関する第一原理解析

    町田 成海、三澤 賢明、毛塚 雄己、鶴田 健二

    日本金属学会2021年秋期(第169回)講演大会  2021.9.16  日本金属学会

     More details

    Event date: 2021.9.14 - 2021.9.17

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  • C3v対称性をもつトポロジカルフォノニック結晶による 弾性波導波路の構造設計

    竹下 弘朗,三澤 賢明,鶴田 健二

    第82回応用物理学会秋季学術講演会  2021.9.12  フォノンエンジニアリング研究会

     More details

    Event date: 2021.9.10 - 2021.9.13

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:同志社大学(オンライン)   Country:Japan  

  • フォノニック結晶を用いたトポロジカル弾性波導波路の設計・計測

    片岡 源樹,三澤 賢明,鶴田 健二

    第82回応用物理学会秋季学術講演会  2021.9.12  フォノンエンジニアリング研究会

     More details

    Event date: 2021.9.10 - 2021.9.13

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:同志社大学(オンライン)   Country:Japan  

  • Optimization of Molecular Characteristics via Machine Learning based on Continuous Representation of Molecules Invited International conference

    Kenji Tsuruta and Kyosuke Sato

    THERMEC '2021  2021.6.3  THERMEC2021 Program Comittee

     More details

    Event date: 2021.6.1 - 2021.6.5

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Vienna (virtual)   Country:Austria  

  • フォノニック構造を用いたトポロジカル音響導波路と非相反伝搬機構の設計 Invited

    鶴田 健二

    第81回応用物理学会秋季学術講演会  2020.9.10  フォノンエンジニアリング研究会

     More details

    Event date: 2020.9.8 - 2020.9.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:同志社大学(オンライン)   Country:Japan  

  • 温暖湿潤気候における日中放射冷却デバイスの特性評価

    第65回応用物理学会春季学術講演会  2018 

     More details

  • 間接遷移型モード変調に基づく非相反音響導波路の構造設計

    日本物理学会2018年秋季大会  2018 

     More details

  • 赤外メタマテリアルの局所光学活性を用いたアミノ酸解析

    2018年度応用物理・物理系学会中国四国支部合同学術講演会  2018 

     More details

  • フォノニック結晶中の空洞共振による導波モード変換を用いた非相反音響導波路

    日本物理学会2018年秋季大会  2018 

     More details

  • Transmission and focusing of ultrasonic wave in silicone by two-dimensional phononic crystal

    The 29th Symposium on Ultrasonic Electronics (USE2018)  2018 

     More details

  • Wideband acoustic absorber by multicomponent metasurfaces and its application to energy harvesting

    The 29th Symposium on Ultrasonic Electronics (USE2018)  2018 

     More details

  • Non-Reciprocal Acoustic Waveguide based on Guided-Mode Conversion by Cavity Resonance in Phononic Crystal

    2018 

     More details

  • Design of Non-Reciprocal Elastic Waveguide based on Indirect Mode Transitions

    2018 

     More details

  • Data-Driven Organic Molecule Design for Optimization of Physical Properties

    2018 

     More details

  • Design of Sound-Absorbing Metasurface toward a Broadband Energy Harvester

    2018 

     More details

  • フォノニック結晶による超音波伝搬制御と光学的可視化

    音響・超音波サブソサイエティ合同研究会  2018 

     More details

  • Super chiral field in infrared metamaterials for D/L-alanine analysis

    2018 

     More details

  • Design of high efficiency elastic wave lens by phononic crystal in silicone

    2018 

     More details

  • Design of two-dimensional phononic crystal in silicone and its application to GRIN lens

    2018 

     More details

  • Reduction of leakage transmission loss for non-reciprocal wave propagation in hetero-phononic structure

    2018 

     More details

  • Absorption Characteristics of Acoustic Metasurface using Multiple Resonant Membranes and their Application to Energy Harvesting

    2018 

     More details

  • Super chiral field in infrared metamaterials for amino acid analysis

    2018 

     More details

  • 十字穴を有するフォノニック結晶のバンドギャップ制御のための解析モデル

    第65回応用物理学会春季学術講演会  2018 

     More details

  • Metaheuristic Ab-initio Optimum Search for Doping Effects in Nanocarbons

    THERMEC2018  2018 

     More details

  • 人工網膜分子(NK5962)のカウンターイオン置換:第一原理分子動力学シミュレーション

    第65回応用物理学会春季学術講演会  2018 

     More details

  • シリコーン中のフォノニック結晶による高効率弾性波レンズの設計

    2018年度応用物理・物理系学会中国四国支部合同学術講演会  2018 

     More details

  • シリコーン中の2次元フォノニック結晶の設計とGRINレンズへの応用

    第63回音波と物性討論会  2018 

     More details

  • ヘテロフォノニック構造を用いた非相反弾性波伝搬における漏洩低減の検討

    2018年度応用物理・物理系学会中国四国支部合同学術講演会  2018 

     More details

  • 多重共振膜構造を用いた音響メタ表面の吸音特性と環境発電への応用

    2018年度応用物理・物理系学会中国四国支部合同学術講演会  2018 

     More details

  • 間接音響遷移に基づく音響ダイオードの数値シミュレーション

    音響・超音波サブソサイエティ合同研究会  2018 

     More details

  • フォノニック結晶のバンドギャップ制御のための理論モデル

    音響・超音波サブソサイエティ合同研究会  2018 

     More details

  • EITメタマテリアル格子と有機分子との共鳴結合を用いた高感度赤外吸収分光

    第65回応用物理学会春季学術講演会  2018 

     More details

  • Numerical Simulation of Non-reciprocal Acoustic Waveguide based on Indirect Interband Transitions

    IEEE International Ultrasonics Symposium  2018 

     More details

  • EIT metamaterial lattice for enhanced sensitivity of infrared molecular detection

    The 65th JSAP Spring Meeting 2018  2018 

     More details

  • Characterization of Daytime Radiative Cooling in Warm and Humid Environment

    The 65th JSAP Spring Meeting 2018  2018 

     More details

  • Effects of counter-ion substitution on properties of artificial-retinal molecule : ab initio molecular dynamics simulations

    The 65th JSAP Spring Meeting 2018  2018 

     More details

  • Analytical Models for Bandgap Control of Phononic Crystals with Cross-holes

    The 65th JSAP Spring Meeting 2018  2018 

     More details

  • 物性最適化のためのデータ駆動型有機分子設計

    2018年応用物理学会秋季学術講演会  2018 

     More details

  • 環境発電デバイス広帯域化のための吸音メタ表面の設計

    2018年応用物理学会秋季学術講演会  2018 

     More details

  • Design of Non-reciprocal Lamb Wave Filter by Heterojunction Phononic Crystals

    IEEE International Ultrasonics Symposium  2018 

     More details

  • 赤外メタマテリアルの局所光学活性を用いたD/L-アラニン解析

    2018年応用物理学会秋季学術講演会  2018 

     More details

  • Design and Assessment of Phononic Crystals for Controlling Ultrasonic Wave via Optical Measurement Method

    IEEE International Ultrasonics Symposium  2018 

     More details

  • Transferable Analytical Model of Phononic Bandgap in Cross-hole Phononic Crystals

    IEEE International Ultrasonics Symposium  2018 

     More details

  • Effect of Defect on Structural and Optical Properties in Methyl-Ammonium Lead Iodide(MAPI) Perovskite via First Principles Calculations

    The 9th International Conference on Multiscale Materials Modeling  2018 

     More details

  • 遺伝的アルゴリズムを用いて自動設計した赤外デジタルメタマテリアル

    第64回応用物理学会春季学術講演会  2017 

     More details

  • Design of non-reciprocal acoustic waveguides by indirect interband transitions

    The 72nd Physical Society of Japan Annual Meeting  2017 

     More details

  • First-principles calculation of amorphization and topology of alpha-Fe2O3

    The 72nd Physical Society of Japan Annual Meeting  2017 

     More details

  • Structure optimization of metal-dielectric multi-layer for high-efficiency daytime radiative cooling

    The 64th JSAP Spring Meeting 2016  2017 

     More details

  • Automated genetic algorithm design of infrared digital metamaterials

    The 64th JSAP Spring Meeting 2016  2017 

     More details

  • Structure optimization of metallodielectric multilayer for high-efficiency daytime radiative cooling

    SPIE Optics + Photonics 2017  2017 

     More details

  • Metaheuristic ab-initio algorithm for designing hetero-doped graphene

    第10回先進セラミックス科学技術国際会議  2017 

     More details

  • 炭素繊維複合材料の界面状態と力学特性に関する分子動力学シミュレーション

    日本金属学会2017年度秋季講演大会  2017 

     More details

  • Automated design of infrared digital metamaterials by Genetic Algorithm

    SPIE Optics + Photonics 2017  2017 

     More details

  • フォノニック結晶中の超音波伝搬と光学的可視化評価

    第 62 回 音波と物性討論会/ 第 9回 ナノレオロジー研究会  2017 

     More details

  • Hierarchical Simulations for Doping Effects in Nanomaterials

    Frontiers in Materials Processing Applications, Research and Technology (FiMPART2017)  2017 

     More details

  • 間接音響遷移に基づく音響ダイオードのFDTD解析

    2017年度応用物理・物理系学会・中国四国支部合同学術講演会  2017 

     More details

  • フォノニック結晶を用いた音響導波路の作製および光学的可視化評価

    2017年度応用物理・物理系学会・中国四国支部合同学術講演会  2017 

     More details

  • 分子動力学法による炭素繊維強化プラスチックの遷移-樹脂界面解析

    2017年度応用物理・物理系学会・中国四国支部合同学術講演会  2017 

     More details

  • 十字穴を有するフォノニック結晶のバンドギャップ制御と作製

    2017年度応用物理・物理系学会・中国四国支部合同学術講演会  2017 

     More details

  • 機械学習法によるタイトバインディングパラメータの抽出

    2017年度応用物理・物理系学会・中国四国支部合同学術講演会  2017 

     More details

  • Cross-Polarized Surface-Enhanced Infrared Spectroscopy by Asymmetric Metamaterials

    MTSA 2017&TeraNano-8  2017 

     More details

  • 十字穴を有するフォノニック結晶のバンドギャップ制御に関する有限要素解析

    第30回計算力学講演会  2017 

     More details

  • メタヒューリスティクスと第一原理計算によるヘテロドープグラフェンの設計アルゴリズム

    日本金属学会2017年度秋季講演大会  2017 

     More details

  • Control and optical visualization of ultrasonic propagation in phononic crystal

    The 38th Symposium on Ultrasonics Electronics (USE 2017)  2017 

     More details

  • 赤外デジタルメタマテリアルの計算機による自動設計と作製

    第30回計算力学講演会  2017 

     More details

  • 3D Chiral Metamaterial with Printed Electronics

    MTSA 2017&TeraNano-8  2017 

     More details

  • Theorical modeling and experimental measurement for bandgap control of phononic crystals

    The 38th Symposium on Ultrasonics Electronics (USE 2017)  2017 

     More details

  • Automated design of infrared digital metamaterials by Genetic Algorithm

    SPIE Optics + Photonics 2017  2017 

     More details

  • Structure optimization of metallodielectric multilayer for high-efficiency daytime radiative cooling

    SPIE Optics + Photonics 2017  2017 

     More details

  • Metaheuristic ab-initio algorithm for designing hetero-doped graphene

    The 10th International Conference on the Science and Technology for Advanced Ceramics (STAC-10)  2017 

     More details

  • Hierarchical Simulations for Doping Effects in Nanomaterials

    Frontiers in Materials Processing Applications, Research and Technology (FiMPART2017)  2017 

     More details

  • Molecular dynamics simulation on CFRP interface

    The 1st Symposium of the Society of Interfacial Material Science  2017 

     More details

  • Acoustic waveguide in phononic crystals and optical visualization

    2017 

     More details

  • Ultrasonic propagation in phononic crystals and optical visualization

    The 62st Symposium on Sono-Physics and Sono-Chemistry / The 9th Scientific Meeting on Nano-Reology  2017 

     More details

  • Bandgap control and fabrication of phononic crystal with cross holes

    2017 

     More details

  • FDTD analysis on acoustic diodes based on indirect interband phononic transitions

    2017 

     More details

  • Machine learning for prediction of the tight-binding parameters

    2017 

     More details

  • CFRP interfacial analysis by molecular dynamics simulation

    2017 

     More details

  • alpha-Fe2O3 のアモルファス化とトポロジーに関する第一原理解析

    2017年日本物理学会年次大会  2017 

     More details

  • CFRP界面の分子動力学シミュレーション

    第1回複合材料界面科学研究会シンポジウム  2017 

     More details

  • 間接バンド間遷移を用いた非相反音響導波路の設計

    2017年日本物理学会年次大会  2017 

     More details

  • Design of hetero-doped graphene by metaheuristic ab-initio algorithm

    2017 Japan Institute of Metals and Materials Fall Meeting  2017 

     More details

  • Molcular-dynamics simulations on interfacial states and mechanical properties of CFRP

    2017 Japan Institute of Metals and Materials Fall Meeting  2017 

     More details

  • Finite element analysis on bandgap control of phononic crystal with cross holes

    JSME 30th Computational Mechanics Division Conference (CMD2017)  2017 

     More details

  • Finite element analysis on bandgap control of phononic crystal with cross holes

    JSME 30th Computational Mechanics Division Conference (CMD2017)  2017 

     More details

  • Theorical modeling and experimental measurement for bandgap control of phononic crystals

    The 38th Symposium on Ultrasonics Electronics (USE 2017)  2017 

     More details

  • Control and optical visualization of ultrasonic propagation in phononic crystal

    The 38th Symposium on Ultrasonics Electronics (USE 2017)  2017 

     More details

  • 金属・誘電体多層膜の構造最適化による高効率日中放射冷却

    第64回応用物理学会春季学術講演会  2017 

     More details

  • Hybrid quantum/classical simulations for dopant segregation and optical response of nanomaterials

    THERMEC’2016 - International Conference on Processing & Manufacturing of advanced Materials  2016 

     More details

  • Hybrid quantum/classical simulations for dopant segregation and optical response of nanomaterials

    THERMEC'2016 - International Conference on Processing & Manufacturing of advanced Materials  2016 

     More details

  • Controlled Fano Resonances in Symmetry-Broken Infrared Metamaterials

    The 63th JSAP Spring Meeting 2016  2016 

     More details

  • Design of composite-structured acoustic metasurface toward wideband energy harvesting

    The 37th Symposium on Ultrasonics Electronics (USE 2016)  2016 

     More details

  • Controlled Fano resonances via symmetry breaking in metamaterials for high-sensitive infrared spectroscopy

    SPIE Optics + Photonics 2016  2016 

     More details

  • Fano-Resonant Asymmetric Metamaterials for Surface-Enhanced Infrared Molecular Detection

    2016 

     More details

  • Design of non-reciprocal acoustic waveguides by indirect interband transitions

    The 37th Symposium on Ultrasonics Electronics (USE 2016)  2016 

     More details

  • 赤外メタマテリアルの構造対称性制御によるファノ共鳴励起

    第63回応用物理学会春季学術講演会  2016 

     More details

  • 界面改質されたグラファイト-樹脂複合材料の第一原理および古典分子動力学解析

    第7回複合材料会議  2016 

     More details

  • Ab initio and classical molecular-dynamics analysis on interface-modified graphite/resin composite

    JCCM-7  2016 

     More details

  • 折り紙メタマテリアルと銀ナノ粒子印刷技術を用いたチューナブル電波吸収体の作製

    IEEE-HISS 2016  2016 

     More details

  • Controlled Fano resonances via symmetry breaking in metamaterials for high-sensitive infrared spectroscopy

    SPIE Optics + Photonics 2016  2016 

     More details

  • Si,P共添加によるα-Fe2O3アモルファス化の第一原理解析

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • Si,P共添加によるα-Fe2O3アモルファス化の第一原理解析

    2016年日本物理学会秋季大会  2016 

     More details

  • Research Topics in Laboratory of Multiscale Device Design in Okayama university

    Seminar at Institute fur Theoretische Physik, Johannes Kepler Univ  2016 

     More details

  • 銀ナノ粒子印刷技術と折り紙構造を用いた電波吸収メタマテリアルの作製

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • メタ表面構造を用いた吸音およびエナジーハーべスティングデバイスの設計

    第 61 回 音波と物性討論会/ 第 8回 ナノレオロジー研究会  2016 

     More details

  • モンテカルロ法を用いた日中放射冷却デバイスの構造最適化

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • 赤外メタマテリアルの構造対称性制御によるファノ共鳴励起と交差偏光特性

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • フレネル法を用いた水中超音波伝搬の光学的可視化

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • 3Dプリンタと選択無電解めっきを用いた電磁メタマテリアル作製

    2016年度応用物理・物理系学会・中国四国支部合同学術講演会  2016 

     More details

  • 太陽光照射下における高効率放射冷却デバイスの設計

    第29回計算力学講演会  2016 

     More details

  • メタ表面構造を用いた吸音およびエナジーハーベスティングデバイスの設計

    第29回計算力学講演会  2016 

     More details

  • Design of non-reciprocal acoustic waveguides by indirect interband transitions

    The 37th Symposium on Ultrasonics Electronics (USE 2016)  2016 

     More details

  • Design of composite-structured acoustic metasurface toward wideband energy harvesting

    The 37th Symposium on Ultrasonics Electronics (USE 2016)  2016 

     More details

  • 誘電体多層膜の構造最適化による日中放射冷却デバイスの設計

    IEEE-HISS 2016  2016 

     More details

  • Fano-Resonant Asymmetric Metamaterials for Surface-Enhanced Infrared Molecular Detection

    IEEE-HISS 2016  2016 

     More details

  • Rectification of Lamb wave propagation in thin plates with piezo-dielectric periodic structures

    The 36th Symposium on Ultrasonics Electronics (USE 2015)  2015 

     More details

  • 28th JSME Computational Mechanics Division

    2015 

     More details

  • Terahertz Wavefront Control by Graphene Metasurface

    2015 MRS Spring Meeting & Exhibit  2015 

     More details

  • アルミナ結晶中のらせん転位に関する大規模分子動力学解析

    日本金属学会2015年春期講演大会  2015 

     More details

  • 3Dプリンタと無電解めっきを用いた3次元電磁メタマテリアル

    2015年度応用物理・物理系学会・中国四国支部合同学術講演会  2015 

     More details

  • デジタルマイクロミラーデバイスを用いたマスクレス露光装置の構築と光メタマテリアルへの応用

    2015年度応用物理・物理系学会・中国四国支部合同学術講演会  2015 

     More details

  • 音波吸収メタ表面の設計と高効率化

    第28回計算力学講演会  2015 

     More details

  • 音波吸収メタ表面の設計と高効率化

    第76回応用物理学会秋季学術講演会  2015 

     More details

  • 3次元プリンタと無電解めっきを用いた3次元電磁メタマテリアルの作製と評価

    平成27年度 (第66回) 電気・情報関連学会中国支部連合大会  2015 

     More details

  • グラファイト-樹脂界面の特性改質の分子動力学シミュレーション

    第28回計算力学講演会  2015 

     More details

  • 圧電-誘電体周期構造を用いた音響ダイオードの設計

    第62回応用物理学会春季学術講演会  2015 

     More details

  • Design of Acoustic Metasurface toward a Perfect Absorber

    The 36th Symposium on Ultrasonics Electronics (USE 2015)  2015 

     More details

  • 機械的剥離法を用いたHfS2原子薄膜の作製と基礎物性の評価

    第62回応用物理学会春季学術講演会  2015 

     More details

  • Design of Acoustic Metasurface toward a Perfect Absorber

    The 36th Symposium on Ultrasonics Electronics (USE 2015)  2015 

     More details

  • Rectification of Lamb wave propagation in thin plates with piezo-dielectric periodic structures

    The 36th Symposium on Ultrasonics Electronics (USE 2015)  2015 

     More details

  • 圧電周期構造を用いた音響ダイオードの設計

    平成26 年度(第65 回) 電気・情報関連学会中国支部連合大会  2014 

     More details

  • 磁気メタマテリアルを用いたサブ波長TEMモード導波管の設計

    平成26年度 (第65回) 電気・情報関連学会中国支部連合大会  2014 

     More details

  • 圧電周期構造を用いた音響ダイオードの設計

    日本機械学会第27回計算力学講演会  2014 

     More details

  • 磁気メタマテリアルを用いたサブ波長TEM モード導波管の設計

    平成26 年度(第65 回) 電気・情報関連学会中国支部連合大会  2014 

     More details

  • Simulating Nanodoping Effect on Materials via Multiscale Methods

    IUMRS-Second International Conference of Young Researchers on Advanced Materials (IUMRS-ICYRAM 2014)  2014 

     More details

  • Terahertz Acoustic Wave on Piezoelectric Semiconductor Film via Large-Scale Molecular Dynamics Simulation

    The 35th Symposium on Ultrasonics Electronics (USE 2014)  2014 

     More details

  • Design and Visualization of Ultrasonic Wave in Phononic Structure for Efficient Energy Transmission

    The 35th Symposium on Ultrasonics Electronics (USE 2014)  2014 

     More details

  • 樹脂製フォノニック結晶による超音波エネルギー輸送・収穫:負の屈折と音響レンズ効果

    第61回応用物理学会春季学術講演会  2014 

     More details

  • 4H-SiC表面の水分解反応:第一原理解析

    第61回応用物理学会春季学術講演会  2014 

     More details

  • Acoustic Wave on Piezoelectric Semiconductor Film via Molecular Dynamics Simulation

    The 15th IUMRS-International Conference in Asia (IUMRS-ICA 2014)  2014 

     More details

  • Dopant Segregation into Screw Dislocation in Alumina: A Hybrid Quantum/Classical Molecular Dynamics Analysis

    The 15th IUMRS-International Conference in Asia (IUMRS-ICA 2014)  2014 

     More details

  • 3C-SiC 表面の水分解素過程に関する第一原理解析

    2014年度第75回応用物理学会秋季学術講演会  2014 

     More details

  • Acoustic Wave on Piezoelectric Semiconductor Film via Molecular Dynamics Simulation

    The 15th IUMRS-International Conference in Asia (IUMRS-ICA 2014)  2014 

     More details

  • Graphene Metasurface for THz Wavefront Control

    JSAP-OSA Joint Symposia 2014  2014 

     More details

  • オーバーサイズ円形導波路内における超音波無線電力伝送

    2014年度第75回応用物理学会秋季学術講演会  2014 

     More details

  • 圧電-誘電体周期構造を用いた音響ダイオードの設計

    平成26年度 (第65回) 電気・情報関連学会中国支部連合大会  2014 

     More details

  • Simulating Nanodoping Effect on Materials via Multiscale Methods

    IUMRS-Second International Conference of Young Researchers on Advanced Materials (IUMRS-ICYRAM 2014)  2014 

     More details

  • アルミナ結晶中のらせん転位近傍へのEr原子偏析: ハイブリッド密度汎関数法/古典分子動力学解析

    日本金属学会2014年春期講演大会  2014 

     More details

  • 圧電性半導体における弾性波伝搬・制御の分子動力学シミュレーション

    第61回応用物理学会春季学術講演会  2014 

     More details

  • グラフェンメタマテリアルの応答解析とTHz 波デバイスへの応用

    2014年度応用物理・物理系学会・中国四国支部合同学術講演会  2014 

     More details

  • 3C-SiC による水分解反応過程と電荷状態解析:第一原理計算

    2014年度応用物理・物理系学会・中国四国支部合同学術講演会  2014 

     More details

  • Dopant Segregation into Screw Dislocation in Alumina: A Hybrid Quantum/Classical Molecular Dynamics Analysis

    The 15th IUMRS-International Conference in Asia (IUMRS-ICA 2014)  2014 

     More details

  • Design and Visualization of Ultrasonic Wave in Phononic Structure for Efficient Energy Transmission

    The 35th Symposium on Ultrasonics Electronics (USE 2014)  2014 

     More details

  • 圧電性半導体薄膜における弾性波伝搬・制御の大規模分子動力学シミュレーション

    日本機械学会第27回計算力学講演会  2014 

     More details

  • FDTD法を用いたグラフェン周期構造のテラヘルツ波応答解析

    日本機械学会第27回計算力学講演会  2014 

     More details

  • 水を充填した導波路の内壁構造が弾性波伝搬に与える影響

    日本機械学会第27回計算力学講演会  2014 

     More details

  • Terahertz Acoustic Wave on Piezoelectric Semiconductor Film via Large-Scale Molecular Dynamics Simulation

    The 35th Symposium on Ultrasonics Electronics (USE 2014)  2014 

     More details

  • 4H-SiC表面の水分解反応:第一原理解析

    日本機械学会第26回計算力学講演会  2013 

     More details

  • アルミナ結晶中のらせん転位近傍への不純物偏析: ハイブリッド量子/古典分子動力学解析

    日本機械学会第26回計算力学講演会  2013 

     More details

  • フォノニック結晶レンズのFDTD解析と超音波実験

    日本機械学会第26回計算力学講演会  2013 

     More details

  • GaAs結晶表面における弾性波伝搬・制御の大規模分子動力学シミュレーション

    日本機械学会第26回計算力学講演会  2013 

     More details

  • 4H-SiC表面の水分解反応:第一原理解析

    2013年度応用物理・物理系学会・中国四国支部合同学術講演会  2013 

     More details

  • Segregation Effect on Dislocation in Alumina: A Hybrid Density-functional/Classical Molecular-dynamics Analysis

    JSAP-MRS Joint Symposia 2013  2013 

     More details

  • GaAs結晶表面における弾性波伝搬・制御の分子動力学シミュレーション

    応用物理学会2013秋季大会  2013 

     More details

  • CNT/GaAsヘテロ太陽電池の第一原理電子状態解析

    日本機械学会第26回計算力学講演会  2013 

     More details

  • Doping Effect on Local Electronic States in Carbon Nanotube/GaAs Interface: An Ab-initio Study

    JSAP-MRS Joint Symposia 2013  2013 

     More details

  • Segregation Effect on Dislocation in Alumina: A Hybrid Density-functional/Classical Molecular-dynamics Analysis

    JSAP-MRS Joint Symposia 2013  2013 

     More details

  • Controlling Surface Acoustic Wave on GaAs Crystal via Molecular Dynamics Analysis

    2013 

     More details

  • CNT/GaAsヘテロ界面の第一原理電子状態解析:界面電荷移動と不純物の効果

    日本物理学会 第68回年次大会  2013 

     More details

  • Doping Effect on Local Electronic States in Carbon Nanotube/GaAs Interface: An Ab-initio Study

    JSAP-MRS Joint Symposia 2013  2013 

     More details

  • アルミナ結晶中の転位近傍への不純物偏析:ハイブリッド量子/古典分子動力学解析

    2013年度応用物理・物理系学会・中国四国支部合同学術講演会  2013 

     More details

  • アルミナ結晶中の転位近傍への添加元素偏析:ハイブリッド量子/古典分子動力学解析

    日本物理学会 第68回年次大会  2013 

     More details

  • Large-scale Molecular Dynamics on Screw Dislocation in Alumina

    The 3rd International Symposium on Advanced Microscopy and Theoretical Calculations (AMTC3)  2012 

     More details

  • Simulating Nanodoping Effect on Materials via Multiscale Methods

    USC-DOE Conference on "Materials Genome: Simulations, Synthesis, Characterization and Manufacturing"  2012 

     More details

  • Controlling Acoustic Wave Propagation on Semiconductor Surface : Large-Scale Molecular Dynamics Simulation

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • Stability of Screw Dislocation in Alumina: A Large-scale Molecular Dynamics Study

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • Density functional calculations of oxygen-vacancy formation at a sigma13 grain boundary in Y-doped alpha-alumina

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • Ab-initio Study of Doping Effect on Optical Response of Graphite Nanotube

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • Characteristics of RF-DC Conversion Circuit for Wireless Power Transmission using the Low Resistance GaN Schottky Barrier Diode

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • Frequency Characteristic of Transmission Efficiency Depended on Matching Condition of Transducer in Ultrasonic Wireless Power Transmission System

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • Controlling Acoustic Wave Propagation on Semiconductor Surface : Large-Scale Molecular Dynamics Simulation

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • An Investigation for Optimum Design of Matching Circuit in Highly Efficient RF-DC Conversion Circuit by Genetic Algorithm

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • Propagation of THz Acoustic Wave on Nanostructured Semiconductor Surface: Large-scale Molecular Dynamics Simulation

    Materials Research Society 2012 Fall Meeting  2012 

     More details

  • Stability and Doping Effect on Dislocation in Alumina: Large-scale Molecular Dynamics and Hybrid Density-functional/Molecular-dynamics Analyses

    Materials Research Society 2012 Fall Meeting  2012 

     More details

  • アルミナ結晶中のらせん転位の安定性に関する大規模分子動力学解析

    日本機械学会第25回計算力学講演会  2012 

     More details

  • シリカガラス中 2 次元フォノニック構造における弾性波伝搬のFDTD 解析

    日本機械学会第25回計算力学講演会  2012 

     More details

  • 第一原理計算による CNT/GaAs ヘテロ界面の電子状態解析

    日本機械学会第25回計算力学講演会  2012 

     More details

  • 半導体・セラミックス中の粒界偏析のハイブリッドMC/MD シミュレーション

    日本機械学会第25回計算力学講演会  2012 

     More details

  • RF-DC変換回路におけるダイオードの等価回路的動作に関する検討

    平成24年度 (第63回) 電気・情報関連学会中国支部連合大会  2012 

     More details

  • 近傍界測定システムによる3m法放射界推定の検討

    平成24年度 (第63回) 電気・情報関連学会中国支部連合大会  2012 

     More details

  • Characteristics of RF-DC Conversion Circuit for Wireless Power Transmission using the Low Resistance GaN Schottky Barrier Diode

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • Frequency Characteristic of Transmission Efficiency Depended on Matching Condition of Transducer in Ultrasonic Wireless Power Transmission System

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • Simulating Nanodoping Effect on Materials via Multiscale Methods

    USC-DOE Conference on "Materials Genome: Simulations, Synthesis, Characterization and Manufacturing"  2012 

     More details

  • ⾼周波整流⽤GaNダイオードを⽤いたRF-DC変換回路の特性

    電子情報通信学会2012年総合大会  2012 

     More details

  • 遺伝的アルゴリズムを⽤いたRF-DC変換回路の⾃動設計

    電子情報通信学会2012年総合大会  2012 

     More details

  • Stability and Doping Effect on Dislocation in Alumina: Large-scale Molecular Dynamics and Hybrid Density-functional/Molecular-dynamics Analyses

    Materials Research Society 2012 Fall Meeting  2012 

     More details

  • An Investigation for Optimum Design of Matching Circuit in Highly Efficient RF-DC Conversion Circuit by Genetic Algorithm

    2012 International Symposiumu on Antennas and Propagation (ISAP2012)  2012 

     More details

  • 構造材料のマルチスケールシミュレーション

    産業科学ナノテクノロジーセンター「第3回若手セミナー」  2012 

     More details

  • Propagation of THz Acoustic Wave on Nanostructured Semiconductor Surface: Large-scale Molecular Dynamics Simulation

    Materials Research Society 2012 Fall Meeting  2012 

     More details

  • ソニック結晶による音響レンズ効果とエネルギー輸送効率Ⅲ:屈折率分布型レンズ構造の基礎検討

    応用物理学会2012春季大会  2012 

     More details

  • 半導体結晶表面における弾性波伝搬制御:大規模分子動力学シミュレーション

    応用物理学会2012春季大会  2012 

     More details

  • シリーズ形およびシャント形RF-DC変換回路の特性に関する考察

    電子情報通信学会2012年総合大会  2012 

     More details

  • トランスデューサの共振周波数および反共振周波数における超音波による無線電力伝送効率

    応用物理学会2012春季大会  2012 

     More details

  • 超音波無線送電のための高効率・広帯域トランスデューサの設計

    日本機械学会第25回計算力学講演会  2012 

     More details

  • Si 結晶の表面弾性波伝搬制御に関する分子動力学解析

    日本機械学会第25回計算力学講演会  2012 

     More details

  • Density functional calculations of oxygen-vacancy formation at a sigma13 grain boundary in Y-doped alpha-alumina

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • ナノ機能元素添加効果のマルチスケールシミュレーション

    科研費特定領域研究「機能元素のナノ材料科学」最終成果報告会  2012 

     More details

  • Large-scale Molecular Dynamics on Screw Dislocation in Alumina

    The 3rd International Symposium on Advanced Microscopy and Theoretical Calculations (AMTC3)  2012 

     More details

  • 超音波無線送電のための高効率・広帯域トランスデューサの設計

    応用物理学会2012秋季大会  2012 

     More details

  • Si 結晶の表面弾性波伝搬制御に関する分子動力学解析

    応用物理学会2012秋季大会  2012 

     More details

  • Stability of Screw Dislocation in Alumina: A Large-scale Molecular Dynamics Study

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • アルミナ結晶中らせん転位の安定性に関する有限温度分子動力学解析

    日本金属学会2012年秋期大会  2012 

     More details

  • Ab-initio Study of Doping Effect on Optical Response of Graphite Nanotube

    IUMRS International Conference on Electronic Materials 2012 (IUMRS-ICEM2012)  2012 

     More details

  • Structures and Local Electronic States of Dislocation Loop in 4H-SiC via an O(N) Tight-binding Study

    2011 

     More details

  • Analyses on spin-orbit coupling effects of a silicon single vacancy via DFT calculations

    2011 

     More details

  • Acoustic Lens Effect and Energy-Transmission Efficiency via Sonic Crystal

    2011 

     More details

  • Experiments of Wireless Power Transmission by Ultrasonic using Highly Efficient Transducers

    2011 

     More details

  • Electronic State and Impurity Effect on Dislocations and Stacking Faults in 4H-SiC:O(N) Tight-binding and Hybrid Classical/Ab Initio Studies

    2011 

     More details

  • Si 表面付近の原子空孔間相互作用:タイトバインディング分子動力学シミュレーション

    日本MRS 第21回学術シンポジウム  2011 

     More details

  • Ab-initio Simulation for Structure and Optical Response of Gemini-HBC

    The 28th Japan-Korea International Seminar on Ceramics  2011 

     More details

  • Diffusion Processes of Lithium Atom in Carbon-based Anode Material for Lithium-ion Secondary Battery: An Ab-initio Study

    The 28th Japan-Korea International Seminar on Ceramics  2011 

     More details

  • DFT計算によるシリコン単原子空孔のスピン軌道相互作用の検討

    日本物理学会第66回春季年次大会  2011 

     More details

  • ソニック結晶による超音波の音響レンズ効果とエネルギー輸送効率

    第58回応用物理学関係連合講演会  2011 

     More details

  • Development of Highly Efficient Transducer for Wireless Power Transmission System by Ultrasonic

    2011 IEEE MTT-S International Microwave Workshop Series(IEEE IMWS-IWPT 2011)  2011 

     More details

  • Multiscale Material Simulations for Segregation Dynamics of Nanodopants

    2011 International Conference on Computational & Experimental Engineering and Sciences (ICCES'11)  2011 

     More details

  • 4H-SiC 結晶中転位の構造と電子状態:タイトバインディング・シミュレーション

    応用物理学会 日本物理学会 中国・四国支部 2011年度 支部学術講演会  2011 

     More details

  • Acoustic Lens using Sonic Crystal for Energy-Transmission Applications

    2011 IEEE MTT-S International Microwave Workshop Series(IEEE IMWS-IWPT 2011)  2011 

     More details

  • 高効率トランスデューサによる超音波無線電力伝送実験

    2011秋季 第72回応用物理学会学術講演会  2011 

     More details

  • 4H-SiC 結晶中転位・積層欠陥の電子状態と不純物効果:O(N)タイトバインディングおよび古典/第一原理ハイブリッド解析

    2011秋季 第72回応用物理学会学術講演会  2011 

     More details

  • |Interaction of Atomic Vacancy of Si near Surface: A Tight-binding Molecular Dynamics Study

    2011 

     More details

  • Acoustic Lens Effect and Energy-Transmission Efficiency using Sonic Crystal II: An Optimization via Multilayer Structure

    2011 

     More details

  • 4H-SiC結晶中転位ループの構造と電子状態:O(N)タイトバインディング解析

    第58回応用物理学関係連合講演会  2011 

     More details

  • Si 結晶中の原子空孔間相互作用に関する大規模分子動力学解析

    日本機械学会第24回計算力学講演会  2011 

     More details

  • Gemini-HBC の構造と光応答に関する第一原理シミュレーション

    日本機械学会第24回計算力学講演会  2011 

     More details

  • マルチスケール手法によるナノ機能元素材料解析

    日本金属学会 2011年秋期講演大会 S1機能元素のナノ材料科学  2011 

     More details

  • 第一原理計算及びハイブリッド法による Li イオン二次電池負極炭素材料中の拡散挙動解析

    日本機械学会第24回計算力学講演会  2011 

     More details

  • 第一原理計算及びハイブリッド量子古典 MD 法による Li イオン二次電池負極炭素材料中の拡散挙動解析

    日本金属学会 2011年秋期講演大会 S1機能元素のナノ材料科学  2011 

     More details

  • アルミナ結晶中のらせん転位に関する大規模分子動力学解析

    日本金属学会 2011年秋期講演大会 S1機能元素のナノ材料科学  2011 

     More details

  • Large-scale Molecular Dynamics Study of Dislocations in Alumina

    The 28th Japan-Korea International Seminar on Ceramics  2011 

     More details

  • Gemini-HBC の構造と光応答に関する第一原理シミュレーション

    日本金属学会 2011年秋期講演大会 S1機能元素のナノ材料科学  2011 

     More details

  • フォノニック結晶による超音波の音響レンズ効果とエネルギー輸送効率

    日本機械学会第24回計算力学講演会  2011 

     More details

  • 半導体結晶表面における弾性波伝搬の大規模分子動力学シミュレーション

    日本機械学会第24回計算力学講演会  2011 

     More details

  • ソニック結晶による音響レンズ効果とエネルギー輸送効率Ⅱ:構造多層化による最適化の検討

    2011秋季 第72回応用物理学会学術講演会  2011 

     More details

  • α−アルミナ結晶中の転位に関する大規模分子動力学解析

    日本金属学会2010秋期講演大会  2010 

     More details

  • 酸化物セラミックスの転位偏析に関するマルチスケール解析

    日本金属学会2010春期講演大会  2010 

     More details

  • 4H-SiC結晶中の点欠陥に関するタイトバインディングシミュレーション

    日本金属学会2010春期講演大会  2010 

     More details

  • Parallel FDTD Simulations on Optical and Acoustic Memataterials

    9th World Congress on Computational Mechanics and 4th Asian Pacific Congress on Computational Mechanics  2010 

     More details

  • 高効率エナジーハーベスティングのためのメタマテリアルの利用

    「メタマテリアルの開発と応用」2010年度第1回研究会  2010 

     More details

  • Si原子空孔の大規模第一原理計算

    特進・ナノエレ・ベンチャー合同研究会  2010 

     More details

  • O(N) タイトバインディング法による4H-SiC 中の転位ループに関する解析

    日本MRS 第20回学術シンポジウム  2010 

     More details

  • DFT 計算による原子空孔局在軌道の四極子モーメントの計算

    日本MRS 第20回学術シンポジウム  2010 

     More details

  • Ab-initio evaluation of quadrupole moment associated with silicon mono-vacancy

    The Forum on the Science and Technology of Silicon Materials 2010  2010 

     More details

  • 双子座型HBCの構造と光応答に関する第一原理シミュレーション

    第12回IEEE広島学生シンポジウム(HISS)  2010 

     More details

  • アルミナ結晶中の転位に関する大規模分子動力学解析

    日本MRS 第20回学術シンポジウム  2010 

     More details

  • Interaction of Si Vacancies at Finite Temperature: A Tight-Binding Study

    The Forum on the Science and Technology of Silicon Materials 2010  2010 

     More details

  • Large-scale molecular dynamics study of dislocations in Alumina

    2010 

     More details

  • Evaluation of quadrupole moment of the localized orbital around silicon vacancy from DFT calculations

    2010 

     More details

  • Structures and Local Electronic States of Dislocation Loop in 4H-SiC via a Linear-scaling Tight-binding Study

    2010 

     More details

  • 電磁メタマテリアルのFDTD解析: 多層ナノ構造中の電磁分散および光共振特性

    日本金属学会2010春期講演大会  2010 

     More details

  • 酸化物セラミックスの転位偏析に関するマルチスケール解析

    日本物理学会第65回年次大会  2010 

     More details

  • Negative Refraction in Phononic Crystal: Acoustic Lens Effect and Energy-Transmission Efficiency

    2010 

     More details

  • Parallel FDTD Simulations on Optical and Acoustic Memataterials

    9th World Congress on Computational Mechanics and 4th Asian Pacific Congress on Computational Mechanics  2010 

     More details

  • Analyses on localized electron orbitals around a silicon single vacancy via DFT calculations

    2010 

     More details

  • Localized electronic state of silicon monovacancy via ab initio calculations

    2010 

     More details

  • シリコン酸窒化物の誘電率の分子動力学計算:組成比と微視構造の影響

    第30 回エレクトロセラミックス研究討論会  2010 

     More details

  • 第一原理計算によるシリコン単原子空孔の局在電子状態

    応用物理学会2010秋季学術講演会  2010 

     More details

  • フォノニック結晶による負の屈折:音響レンズ効果とエネルギー輸送効率

    応用物理学会2010秋季学術講演会  2010 

     More details

  • O(N)タイトバインディング法による4H-SiC 結晶中の転位構造の解析

    日本金属学会2010秋期講演大会  2010 

     More details

  • DFT計算によるシリコン単原子空孔の局在電子軌道の解析

    日本物理学会2010秋季大会  2010 

     More details

  • Parallel FDTD Simulations on Optical and Acoustic Memataterials

    Materials Research Society 2009 Fall Meeting, Symposium "Metamaterials--From Modeling and Fabrication to Application"  2009 

     More details

  • 電磁メタマテリアルによる光閉じ込め構造のFDTDシミュレーション

    日本機械学会第22回計算力学講演会・オーザナイズドセッション「フォトニック・フォノニック構造の設計とシミュレーション」  2009 

     More details

  • 2 次元フォノニック結晶の音波伝搬シミュレーション;負の屈折とレンズ効果

    日本機械学会第22回計算力学講演会日本機械学会第22回計算力学講演会・オーザナイズドセッション「フォトニック・フォノニック構造の設計とシミュレーション」  2009 

     More details

  • Density-Functional Analysis on Vacancy Oribital and its Elastic Response of Silicon

    Materials Research Society 2009 Fall Meeting, Symposium "Reliability and Materials Issued of Semiconductor Optical and Electrical Devices"  2009 

     More details

  • ハイブリッド量子/古典分子動力学法によるアルミナ転位運動と添加元素効果解析

    日本機械学会第22回計算力学講演会・オーザナイズドセッション「固体物理/流体物理のマルチフィジックス/マルチスケール解析」  2009 

     More details

  • 電磁メタマテリアルによる光閉じ込め構造のFDTDシミュレーション

    科研費・特定領域研究「機能元素のナノ材料科学」第2回若手の会  2009 

     More details

  • マルチスケール・ナノ材料解析:格子不整合領域のダイナミクスと機能元素挙動

    科研費・特定領域「機能元素のナノ材料科学」第2回公開シンポジウム  2009 

     More details

  • 4H-SiC結晶中の点欠陥に関するタイトバインディングシミュレーション

    科研費・特定領域研究「機能元素のナノ材料科学」第2回若手の会  2009 

     More details

  • FTDT法による2次元フォノニック結晶の音波伝搬シミュレーション:構造複合化の効果

    科研費・特定領域研究「機能元素のナノ材料科学」第2回若手の会  2009 

     More details

  • シリコン中の局在欠陥軌道の第一原理的評価と弾性定数ソフト化

    日本物理学会 2009年秋季大会(25aPS-131)  2009 

     More details

  • アルミナ中の転位運動と添加元素効果:ハイブリッド量子/古典分子動力学

    日本セラミックス協会 第22回秋季シンポジウム「機能元素のナノ材料科学」  2009 

     More details

  • 分岐したスピン鎖におけるエンタングルメントの生成とノイズの影響

    日本物理学会 2009年秋季大会(26pZE-6)  2009 

     More details

  • 量子古典ハイブリッド手法によるナノ構造材料の力学物性・電磁応答解析

    第18回日本MRS学術シンポジウム・セッションJ「計算機シミュレーションによる格子欠陥やナノ構造の解明:新規材料創製を目指して」  2009 

     More details

  • FDTD法による2次元フォノニック結晶の音波伝搬シミュレーションII:構造複合化の効果

    日本金属学会 2009年 春期大会,公募シンポジウム S4 機能元素のナノ材料科学  2009 

     More details

  • RC-FDTD法によるナノ構造メタマテリアルの電磁界シミュレーション

    日本金属学会 2009年 春期大会,公募シンポジウム S5 計算材料科学のフロンティア:新たな飛躍を目指して  2009 

     More details

  • Hybrid Quatum/Classical Approaches to Nano- and Meta-Materials

    2009 International Conference on Computational & Experimental Engineering and Sciences (ICCES'09)  2009 

     More details

  • α-アルミナ結晶中の積層欠陥と転位の分子シミュレーション

    日本金属学会 2009年 春期大会,公募シンポジウム S4 機能元素のナノ材料科学  2009 

     More details

  • 機能元素のナノ材料科学に対するマルチスケール計算科学的アプローチ

    日本金属学会 2009年春期講演大会 S4機能元素のナノ材料科学  2009 

     More details

  • シリコン結晶中原子空孔の歪み場・弾性特性の解析:古典及び半経験的タイトバインディング分子動力学

    日本物理学会 第64回年次大会  2009 

     More details

  • 電磁メタマテリアルによる光閉じ込め構造のFDTDシミュレーション

    日本金属学会 2009年 春期大会,公募シンポジウム S4 機能元素のナノ材料科学  2009 

     More details

  • 古典写像法による2次元電子系の解析:有限温度の場合

    日本物理学会 第63回年次大会 (23aTE-6)  2008 

     More details

  • 電磁メタマテリアルにおけるエバネセント波増幅特性:並列FDTDシミュレーション

    日本鉄鋼協会・日本金属学会中国四国支部第15回「若手フォーラム」  2008 

     More details

  • Ni表面における炭素原子挙動:タイトバインディングシミュレーション

    日本鉄鋼協会・日本金属学会中国四国支部第15回「若手フォーラム」  2008 

     More details

  • 2次元フォノニック結晶界面における音波の負の屈折:FDTDシミュレーション

    日本鉄鋼協会・日本金属学会中国四国支部第15回「若手フォーラム」  2008 

     More details

  • 原子空孔を含むSi結晶の弾性定数の温度依存性:TBMDおよびDFT解析

    日本物理学会 第63回年次大会 (24pYF-6)  2008 

     More details

  • 古典写像法による電子系の解析:2次元有限系の Wigner 結晶化

    日本物理学会 2008年秋季大会 (22pRB-5)  2008 

     More details

  • シリコン単原子空孔の大規模第一原理計算:従来の知見の再検証

    日本物理学会 2008年秋季大会 (21pRB-5)  2008 

     More details

  • シリコン単原子空孔の基底状態の再検討

    日本物理学会 2008年秋季大会 (21aRB-10)  2008 

     More details

  • 2次元フォノニック結晶における音波伝播の FDTD シミュレーション

    特定領域研究「機能元素のナノ材料科学」第一回若手の会  2008 

     More details

  • ナノ構造メタマテリアルの並列 FDTD シミュレーション

    日本金属学会 2008年春期(第142回)講演大会, S3 機能元素のナノ材料科学  2008 

     More details

  • Hybrid quantum/classical molecular dynamics for impurity-segregated nanostructures

    The 1st International Symposium on Advanced Microscopy and Theoretical Calculations (AMTC1)  2008 

     More details

  • 並列 FDTD シミュレーション法を用いたメタマテリアルの電磁界解析

    特定領域研究「機能元素のナノ材料科学」第一回若手の会  2008 

     More details

  • アルミナ結晶中の積層欠陥形成過程の分子シミュレーション

    2008年度 応用物理学会中四国支部学術講演会 (Dp-03)  2008 

     More details

  • 分散型DNGメタマテリアルによる光閉じ込め構造:FDTDシミュレーション

    2008年度 応用物理学会中四国支部学術講演会 (Bp-08)  2008 

     More details

  • スピン鎖による情報伝達とエンタングルメント生成

    日本物理学会 2008年秋季大会 (20pZD-10)  2008 

     More details

  • Finite two-dimensional systems of electrons at zero and finite temperatures: simulations based on classical-map hypernetted chain method

    14th International Congress on Plasma Physics (ICPP2008)  2008 

     More details

  • ナノ構造メタマテリアルの並列 FDTD シミュレーションII:ナノ微粒子サイズ効果の影響

    日本金属学会 2008年 秋期大会,公募シンポジウム S2 機能元素のナノ材料科学  2008 

     More details

  • α-Al2O3 の欠陥と不純物挙動に関するマルチスケール解析:ハイブリッド量子/古典分子動力学計算

    日本金属学会 2008年 秋期大会,公募シンポジウム S2 機能元素のナノ材料科学  2008 

     More details

  • タイトバインディング法を用いた炭素固溶 Ni 結晶のモンテカルロシミュレーション

    日本金属学会 2008年 秋期大会,公募シンポジウム S2 機能元素のナノ材料科学  2008 

     More details

  • 2次元フォノニック結晶における音波伝搬の FDTD シミュレーション

    日本金属学会 2008年 秋期大会,公募シンポジウム S2 機能元素のナノ材料科学  2008 

     More details

  • 古典写像法による電子系の解析:2次元2層系のスピン分極

    日本物理学会第62回年次大会 (22aWA-9)  2007 

     More details

  • 炭化珪素ナノワイヤ/アモルファス複合材料の大規模 TBMD シミュレーション

    日本金属学会2007年春期講演大会 シンポジウムS8 機能元素状態解析の新展開:ナノテク基盤から実材料開発へ (S8・17)  2007 

     More details

  • クーロンおよび湯川クラスターの振動スペクトル

    日本物理学会 2007年春季大会 (19pQE-16)  2007 

     More details

  • 分子シミュレーションにおけるマルチスケール化の試み:特に時間領域について

    研究会 Functional Aspects of Biological Macro-Molecules and Their Dynamical Mechanisms  2007 

     More details

  • ハイブリッド MD/TBMD シミュレーションによる Si 結晶欠陥中の水素原子の挙動解析

    日本金属学会2007年春期講演大会 シンポジウムS8 機能元素状態解析の新展開:ナノテク基盤から実材料開発へ (S8・18)  2007 

     More details

  • 半導体欠陥中の不純物挙動:ハイブリッド量子・古典分子動力学シミュレーション

    日本金属学会中国四国支部・第100回記念・金属物性研究会  2007 

     More details

  • Multiscale molecular dynamics for nanophase and nanocomposite materials

    International Symposium on Plasticity 2007, Symposium SuM-1 "Interfaces and Composite Materials under Harsh Conditions I"  2007 

     More details

  • Si原子空孔の大規模第一原理・分子動力学計算

    第68回応用物理学会秋季学術講演会 (5p-ZN-5), シンポジウム 「機能デバイスを支えるシリコン結晶基盤技術― 次世代ULSIから環境デバイスまで ― 」  2007 

     More details

  • FDTD 法による分散型DNG 媒質の電磁界解析:電磁界イメージの再焦点化

    応用物理学会 中国四国支部, 日本物理学会 中国支部・四国支部, 日本物理教育学会 中国四国支部, 2007 年度 支部学術講演会 (Fp-2)  2007 

     More details

  • 2次元電子系の基底状態:古典写像法を用いた分子動力学シミュレーション

    日本物理学会 2007年春季大会 (19pWB-10)  2007 

     More details

  • Large-scale ab-initio/molecular-dynamics study on Si vacancy

    THE FORUM ON THE SCIENCE AND TECHNOLOGY OF SILICON MATERIALS 2007  2007 

     More details

  • Si結晶中原子空孔の電子状態と振動モード:第一原理およびタイトバインディング計算

    日本物理学会第62回年次大会 22pTD-10)  2007 

     More details

  • Large-scale FDTD Simulations on Optical and Acoustic Metamaterials

    APCOM'07/EPMESC XI, Mini-symposium "Ultrascale Hierarchical Simulations on High-End Parallel and Distributed Computers"  2007 

     More details

  • 炭化珪素ナノワイヤ/アモルファス複合材料の破壊過程大規模TBMD シミュレーション

    日本金属学会, 複合材料 Composite Materials (1), (620), 2007年秋期(第141回)大会  2007 

     More details

  • 古典写像法による電子系の解析:2次元有限系のスピン分極

    日本物理学会第62回年次大会 (22aWA-11)  2007 

     More details

  • ダイヤモンド中の Ni 関連欠陥の電子状態と磁気特性:Tight-Binding 分子動力学解析

    日本金属学会, 2006年春期(第138回)大会, シンポジウム S4 ナノ構造設計によるセラミックス材料の新展開  2006 

     More details

  • 確率差分方程式に基づく長時間分子動力学シミュレーション

    日本金属学会,2006年秋季講演大会,計算科学・材料設計(Computational Materials Science)  2006 

     More details

  • Si結晶中の点欠陥について:計算機シミュレーションによる考察

    科研費・特別推進研究「電荷揺らぎに由来する強相関量子相の研究」第2回研究会  2006 

     More details

  • ナノ構造 Si 中の水素原子拡散:ハイブリッド MD/TBMD シミュレーション

    日本金属学会, 2006年秋期大会, シンポジウム S4 ナノ構造設計によるセラミックス材料の新展開(2)  2006 

     More details

  • ダイヤモンド結晶中転位・粒界への Ni 原子偏析過程の Tight-Binding 分子動力学解析

    日本金属学会2006年秋期大会・シンポジウムS5ナノ構造設計によるセラミックス材料の新展開  2006 

     More details

  • Si結晶中の水素原子拡散:ハイブリッドMD/TBMDシミュレーション

    日本物理学会2006年秋季大会  2006 

     More details

  • カーボンナノチューブ/Ni界面のタイトバインディング分子動力学シミュレーション

    日本物理学会2006年秋季大会  2006 

     More details

  • Multiscale Simulations of Impurity Segregation in Nanostructured Materials

    The Second IEEE/ACM International Workshop on High Performance Computing for Nano-science and Technology (HPCNano06)  2006 

     More details

  • 3次元湯川クラスターの融解に関する粒子シミュレーション

    日本物理学会 2006年秋季大会 (26aQB-11)  2006 

     More details

  • Multiscale Molecular Dynamics Simulations of Nanostructured Materials

    THERMEC 2006--International Conference on Processing & Manufacturing of Advanced Materials  2006 

     More details

  • Dynamics of melting of spherical Yukawa and Coulomb clusters

    WORKSHOP ON NON-NEUTRAL PLASMAS  2006 

     More details

  • 量子電子液体に対する古典写像法におけるパラメータの検討

    日本物理学会 第61回年次大会 (28aXH-11)  2006 

     More details

  • Melting of spherical Yukawa and Coulomb clusters

    7th Workshop on Fine Particle Plasmas, Generation, Growth, Behavior, and Control of Fine Particles in Plasmas, O - 6  2006 

     More details

  • 微小重力下においてプラズマ中微粒子の形成するクラスターの構造と融解:シミュレーションと理論

    日本マイクログラビティ応用学会 第22回学術講演会 (JASMAC-22), A136  2006 

     More details

  • 微小重力を含む等方的環境における微粒子クラスターの融解シミュレーション

    日本物理学会 第61回年次大会 (27aUC-8)  2006 

     More details

  • Ni 原子を添加したダイヤモンドの電子状態と磁気特性: タイトバインディング分子動力学シミュレーション

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • Si結晶粒界のTBMDおよびハイブリッドMD/TBMDシミュレーション:電子状態の局在性および水素拡散

    日本金属学会 2005年春期大会  2005 

     More details

  • タイトバインディング法による半導体ナノ構造中の電子ダイナミクス

    日本物理学会 第60回年次大会  2005 

     More details

  • 並列FDTD法による大規模電磁界シミュレーション:フォトニック結晶への応用

    第24回 日本シミュレーション学会大会  2005 

     More details

  • Structure and dynamics of spherical Yukawa clusters

    International Conference on Strongly Coupled Coulomb Systems (SCCS 2005)  2005 

     More details

  • 確率差分方程式による超長時間分子動力学シミュレーション:Cu基板上の膜形成過程への適用検討

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • グラファイト/C60複合系における動摩擦過程のモンテカルロ・シミュレーション

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • Si結晶粒界のTBMDおよびハイブリッドMD/TBMDシミュレーション:電子状態の局在性および水素拡散

    日本物理学会 第60回年次大会  2005 

     More details

  • 分子動力学法による微小重力下のダスト粒子の構造解析

    日本物理学会 第60回年次大会  2005 

     More details

  • シェルモデルによる微小重力下のダストプラズマの構造解析

    日本物理学会 2005年秋季大会  2005 

     More details

  • Simulating Impurity-Segregated Nanostructures and Thin-Film Formation via Multisclae Molecular-Dynamics Approaches

    Invited Seminar at Center for Nanotechnology, NASA Ames Research Center.  2005 

     More details

  • 2次元有限領域の電子液体の古典写像法による解析

    日本物理学会 2005年秋季大会  2005 

     More details

  • 確率差分方程式に基づく超長時間スケールの分子動力学シミュレーション

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • ダスト粒子の球状クラスターの構造解析

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • 2次元有限領域の電子液体の分布

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • グラファイト/C60複合系ナノ・ベアリングの分子シミュレーション

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • タイトバインディング法によるナノ構造中の電子伝搬特性の解析

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • タイトバインディング分子動力学法によるダイアモンド中のNi原子の磁気特性の解析

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • 水素原子を添加したSi結晶のタイトバインディングおよびハイブリッド量子/古典分子動力学シミュレー ション

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • 2次元有限領域の電子液体の古典写像法による解析

    日本物理学会 中国支部・四国支部、応用物理学会 中国四国支部, 2005年度支部学術講演会  2005 

     More details

  • Simulating Impurity-Segregated Nanostructures and Thin-Film Formation via Multisclae Molecular-Dynamics Approaches

    International Conference on Computational and Experimental Engineering and Science, Symposium Materials by Design: Nano to Micro Scale Simulations and Experiments  2005 

     More details

  • グリーン関数と時間依存シュレーディンガー方程式によるナノ構造中の電子伝搬特性の解析

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • ダイヤモンド中のNi関連欠陥:タイトバインディング分子動力学シミュレーション

    第16回日本MRS学術シンポジウム, Session O「ナノ界面の新機能-化学的・機械的・電子的機能の解明と設計」  2005 

     More details

  • グラファイト/C60複合系ナノ・ベアリングの分子シミュレーション

    第16回日本MRS学術シンポジウム, Session O「ナノ界面の新機能-化学的・機械的・電子的機能の解明と設計」  2005 

     More details

  • Structure formation of Yukawa (dust) particles in dusty plasmas in an isotropic environment

    6th Workshop on Fine Particle Plasmas (第6回微粒子プラズマ研究会)  2005 

     More details

  • Melting of Yukawa clusters of dust particles in dusty plasmas

    6th Workshop on Fine Particle Plasmas (第6回微粒子プラズマ研究会)  2005 

     More details

  • 並列FDTD 法によるフォトニック結晶導波路の構造最適化

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • 水素原子を添加したSi 結晶のハイブリッド量子/古典分子動力学シミュレーション

    第7回IEEE広島学生シンポジウム  2005 

     More details

  • Si および SiC 粒界の安定性解析:MD, TBMD,およびハイブリッド MD/TBMD シミュレーション

    日本セラミックス協会 2004年年会  2004 

     More details

  • ナノ多結晶体シミュレーションの現状と課題

    ナノ材料のマルチスケールデザイン  2004 

     More details

  • 確率差分方程式による密度汎関数分子動力学法の高速化の検討

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • タイトバインディング分子動力学法によるSi結晶中の水素拡散の解析

    日本物理学会 第59回年次大会  2004 

     More details

  • タイトバインディング分子動力学法によるSi結晶およびSi粒界中の水素拡散の解析

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • タイトバインディング分子動力学法によるNiクラスターの解析

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • グラファイト/C60 複合系における動摩擦過程のモンテカルロシミュレーション

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • タイトバインディング法によるシリコンナノワイヤの電子伝導

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • Parallel TBMD, Hybrid Classical/TB-MD, and their Application to Interfacial Phenomena in Nanostructured Semiconductors

    Second International Conference on Multiscale Materials Modeling  2004 

     More details

  • セラミックス・半導体ナノ微粒子系の界面現象のシミュレーション

    第14回 格子欠陥フォーラム -固体強度に関するモデリングとシミュレーション-  2004 

     More details

  • Structure Formation in Dusty Plasmas under Microgravity

    Generation, Growth, Behavior, and their Control of Fine Particles in Plasmas -5th Workshop on Fine Particle Plasmas-第5回微粒子プラズマ研究会- プラズマ中微粒子の発生・成長と挙動、およびその制御  2004 

     More details

  • 半導体ナノワイヤにおける電子ダイナミクス

    日本物理学会 第59回年次大会  2004 

     More details

  • 並列 TBMD およびハイブリッド MD/TBMD 法による Si 結晶粒界安定性と水素拡散

    日本金属学会 2004年秋期大会  2004 

     More details

  • クーロンクラスターの大規模分子動力学シミュレーション:有限温度解析

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • 計算グリッドを活用した並列TBMDおよびハイブリッドMD/TBMDシミュレーション:粒界安定性解析への応用

    日本セラミックス協会 第17回秋季シンポジウム  2004 

     More details

  • 分子動力学法による微小重力系ダスト粒子の構造解析

    日本物理学会中国支部・四国支部、応用物理学会中国四国支部物理教育学会四国連絡会議 2004年度支部学術講演会  2004 

     More details

  • The Size Dependence of the Effective Potentials of Ferromagnetic Clusters within the Framework of DFT Scheme

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • SiおよびSiC粒界の安定性解析:MD/TBMDシミュレーション

    日本セラミックス協会2003年年会  2003 

     More details

  • SiおよびSiCのナノ構造における粒界形成と安定性:並列TBMDおよびハイブリッドMD/TBMDシミュレーション

    日本物理学会2003年秋季大会  2003 

     More details

  • SiおよびSiC微粒子間接合界面のMD/TBMDシミュレーション

    日本金属学会2003年春季(第132回)大会  2003 

     More details

  • Stability of High-Energy Grain Boundaries in Nanocrystalline Si and SiC: Parallel MD, Tight-Binding MD, and Hybrid Tight-Binding/Classical MD Studies

    Materials Research Society Fall Meeting 2003  2003 

     More details

  • ナノ構造 Si/SiC の粒界形成と安定性:並列 TBMD およびハイブリッド MD/TBMD シミュレーション

    日本金属学会2003年秋期大会  2003 

     More details

  • Stability of Grain Boundaries in Nanostructured Si and SiC: A molecular dynamics study

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • Parallel TBMD and Hybrid MD/ TBMD Simulations of Nanostructured Ceramics

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • Hydrogen diffusion in Si: A tight-binding molecular dynamics study

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • Tight-binding approach to electron transport in nanostructured semiconductors and their interfaces

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • A DFT Study of the Electronic Structure of Transition Metal Clusters

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • Diffusion Mechanisms of Impurities and Point Defects in Silicon: Tight-Binding Molecular Dynamics Simulation

    IUMRS-ICAM2003, Symposium D9:"Multiscale Design of Nano-materials"  2003 

     More details

  • Collaborative Simulation Grid: Multiscale Quantum-Mechanical/Classical Atomistic Simulations on Distributed PC Clusters in the US and Japan

    15th Annual SuperComputiong Conference (SC2002)  2002 

     More details

  • クーロンクラスターの基底状態と構造転移

    日本物理学会第57回年次大会  2002 

     More details

  • 閉じこめられた湯川系:微小重力下の一成分および多成分系のシミュレーションと理論 III

    日本物理学会第57回年次大会  2002 

     More details

  • シリコン結晶粒界におけるアモルファス層の安定性解析:分子動力学シミュレーション

    日本物理学会中国支部・四国支部,応用物理学会中国四国支部 2002年度支部例会  2002 

     More details

  • クーロンクラスターの融解

    日本物理学会中国支部・四国支部,応用物理学会中国四国支部 2002年度支部例会  2002 

     More details

  • Siアモルファス粒界の安定性解析:MD/TBMDシミュレーション

    日本物理学会2002年秋季大会  2002 

     More details

  • 2次元ダスト結晶中の微粒子の遮蔽長と電荷

    日本物理学会2002年秋季大会  2002 

     More details

  • Screening Length and Electric Charge of Dust Particles

    Fine Particle Plasma: Basis and Applications - 第3回ダストプラズマ研究会  2002 

     More details

  • セラミックス・ナノ微粒子系の原子論的シミュレーション

    第8回ホソカワ粉体工学シンポジウム, 機能性微粒子の設計--粒子設計のためのシミュレーション  2002 

     More details

  • 酸化チタン・ナノ構造体の焼結過程:電荷可変分子動力学シミュレーション

    日本セラミックス協会 2002年年会  2002 

     More details

  • Tight-binding study of nanocrystalline silicon carbide: Dynamics of neck formation, atomic diffusion, and electron mobility

    Mardi Gras Conference 2001 "Multiscale Simulation, Theoretical, and Experimental Approaches of Deformation, Friction, and Fracture"  2001 

     More details

  • 大規模並列分子動力学計算ー計算機援用による欠陥・界面制御を目指して

    日本物理学会領域10シンポジウム招待講演  2001 

     More details

  • 第一原理/半経験的計算法にもとづく粒子集合体のマルチスケールモデリング

    シンポジウム「粒子集合体の自己組織化過程と機能発現」  2000 

     More details

  • 第一原理/半経験的計算法にもとづく粒子集合体のマルチスケールモデリング

    シンポジウム「粒子集合体の自己組織化過程と力学的機能発現」  2000 

     More details

  • Tight-Binding Molecular Dynamics of Ceramic Nanocrystals using Parallel PC Cluster

    International Workshop on Fine Ceramics 2000 "Grain Boundary Engineering in Ceramics: From Grain Boundary Phenomena to Grain Boundary Quantum Structures"  2000 

     More details

  • Parallel Tight-Binding Simulations of Nanophase Ceramics: Atomic and Electronic Transport at Grain Boundaries

    Materials Society Fall Meeting: Symposium Z "Multiscale Materials Modelling"  2000 

     More details

  • 並列分子動力学計算の実状と材料科学への応用

    日本材料学会第48期第3回分子動力学部門委員会講演会  1999 

     More details

  • Tight-Binding Molecular Dynamics Study of Si-based Materials on Parallel PC Cluster

    International Meeting on Thermo-Mechanical and Electrical Properties of High-Temperature Materials  1999 

     More details

  • Tight-binding molecular dynamics of ceramic nanocrystals using PC-based parallel machines

    Materials Research Society Fall Meeting '99, "Nanophase and Nanocomposite Materials III"  1999 

     More details

▼display all

Works

  • 岡山大学知恵の見本市2015

    2015

     More details

Awards

  • Symposium on Ultrasonic Electronics : Best Paper Award

    2020.11   Topologically robust sound wave transport in two-dimensional phononic crystal with a circular rod arrangement in water

    Kenshi Okunoand Kenji Tsuruta

     More details

    Award type:Award from international society, conference, symposium, etc.  Country:Japan

Research Projects

  • 極超音波トポロジカルフォノニクスの開拓と多機能弾性波デバイス開発

    2021.07 - 2026.03

    JSPS  KAKENHI  基盤研究(S)

      More details

    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\159250000 ( Direct expense: \122500000 、 Indirect expense:\36750000 )

  • Development of Ultrasonic Topological Phononics for Multifunctional Elastic Wave Devices

    Grant number:21H05020  2021.07 - 2026.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (S)

    鶴田 健二, 竹澤 晃弘, 松田 理, 畑中 大樹, O・B Wright

      More details

    Grant amount:\159250000 ( Direct expense: \122500000 、 Indirect expense:\36750000 )

    本研究では,計算科学的バンド設計に基づいてトポロジーで保護されたエッジモードの発現を予測,力学系にモデル化・可視化,その知見からエッジモードを介した極めて低損失な音波・弾性波伝搬実現を目指している。初年度は各班で以下の取組・成果が得られた。
    【(岡大+早大)班】 これまでに設計したC3v対称性を持つ水中2次元フォノニック構造を薄膜系に拡張し,kHz~MHz帯でエッジモードが発現するフォノニック構造を設計した。並行して,既知構造をベースに,位相最適化法を用いてより高いロバスト性を持つ最適構造探索に成功,また,それらのプロトタイプ構造を3Dプリンタで試作し,レーザードップラー計測を行った。一方,GHz帯の設計構造は北大班ならびにNTT班で試作・評価を実施中である。
    【北大班】 すでに着手しているフォノニック構造中を伝搬する表面弾性波の時間分解計測による可視化については,強誘電体基板上の銅ピラー構造によるフォノニック結晶で分散関係取得のための予備的な測定を行った。マクロスコピックなメカニカルフォノニック結晶におけるトポロジカルエッジモードの可視化については,回転可能なメカニカルグラフェン構造を設計・製作し,モーションキャプチャーシステムによる同構造の振動測定と解析を進めている。
    【NTT班】(岡大+早大)班がGHz帯で設計したトポロジカルフォノニック導波路構造をMEMS作製技術の援用により試作し,エッジモード励起も確認した。並行して,磁性体装荷のGHzフォノニック結晶素子を作製し,強磁性マグノンによる共振周波数とQ値の変化を確認した。同時に,有限要素法を用いた数値解析法を構築し,計算による当該素子構造における磁気弾性変調効果のシミュレーションを行った。
    また,代表者・分担者・協力研究者による「トポロジカルフォノニクス研究会」を年度内に4回オンライン開催し多数の参加者を得ている。

    researchmap

  • Beyond5G時代に向けたトポロジカル・ナノフォノニクス開

    2021.07 - 2023.03

    JSPS  KAKENHI  挑戦的研究(萌芽)

      More details

    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\6500000 ( Direct expense: \5000000 、 Indirect expense:\1500000 )

  • Development of Topological Nanophononics for the Beyond 5G Era

    Grant number:21K18877  2021.07 - 2023.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Research (Exploratory)

    鶴田 健二, 三澤 賢明, 大村 訓史, 羽田 真毅

      More details

    Grant amount:\6500000 ( Direct expense: \5000000 、 Indirect expense:\1500000 )

    本研究では,近年,波動伝搬のロバスト性により注目が集まるトポロジカル絶縁体の概念を,音波・弾性波に拡張した“トポロジカル・フォノニクス”により,Beyond 5G時代の超高周波弾性波デバイスの動作原理の理論実証を目指している。初年度の実施実績・成果を,全期間を通した達成目標項目ごとに以下に記す。
    (A)原子レベルのトポロジカル相界面の局在フォノン伝搬理論確立
    フォノンバンド計算によるトポロジカル相界面のエッジ状態を持ちうる物質とその結晶粒界構造,および人工周期構造を探索している。今年度は特に,BN基板上のグラフェン構造に着目し,モアレ構造を持つその界面に対するМD計算を実施し,有限温度でTHz領域のフォノン状態密度などといった基礎的特性について知見を得ている。
    (B)トポロジカル相界面に対する光励起による局在フォノン制御
    原子間の結合状態を光励起で変化させることによる振動状態の変化を,線形応答理論に基づく密度汎関数法計算ならびに時間依存密度汎関数法に基づく第一原理МDシミュレーション法で試みている。対象例として,上記グラフェン/BN構造におけるヘテロ接合系(モアレ構造)でエネルギーがどのように片方の層からもう一方の層へと遷移するかを試みている。
    一方,電子線回折実験としては,CNTとBNNTのヘテロ接合を作製し、CNTを光励起したときにBNNTにどのようにエネルギー(振動)が伝わるのかを実験しており,計算と実験の両面から,本現象の微視的メカニズムの解明に向けた解析を実施している。

    researchmap

  • 化学、計算科学、医学を融合した感光色素を用いた医療用材料およびその関連機器の開発

    2020.06 - 2021.03

    岡山県  特別電源所在県科学技術振興事業  医療・福祉・健康分野

    内田哲也

      More details

    Authorship:Coinvestigator(s)  Grant type:Competitive

    Grant amount:\1705000 ( Direct expense: \1550000 、 Indirect expense:\155000 )

  • Development of ultra high strength more than 6GPa ultra light wegiht carbon nanotube spun yarn

    Grant number:18H01708  2018.04 - 2021.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    HAYASHI Yasuhiko

      More details

    Grant amount:\17810000 ( Direct expense: \13700000 、 Indirect expense:\4110000 )

    In this study, carbon nanotube (CNT) yarns were fabricated from tall and high-density, few-walled CNT forest synthesized on the substrate by dry spinning method to achieve CNT yarns with tensile strength exceeding the strength of carbon fibers, which is a benchmark for practical use. The shape and diameter change of the catalytic metal particles from room temperature to the initial temperature of CNT synthesis was clarified, which enabled the selective synthesis of double-layer CNTs. We also found that the removal of residual amorphous carbon and the structural change to graphene occurred simultaneously when the entire CNT yarn was heated by joule heating in vacuum and extreme ethane gas. Furthermore, by using a spinning technique to orient the CNTs in one direction, a high strength of over 2.5 GPa was achieved.

    researchmap

  • フォノニック情報処理実現に向けた高効率音響ダイオード・スイッチの開発

    2017.07 - 2021.03

    JSPS  KAKENHI  挑戦的研究(萌芽)

      More details

    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\6500000 ( Direct expense: \5000000 、 Indirect expense:\1500000 )

  • Development of Acoustic Diode/Switch toward Realization of Phononic Information Processing

    Grant number:17K19035  2017.06 - 2021.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Research (Exploratory)

    TSURUTA Kenji

      More details

    Grant amount:\6500000 ( Direct expense: \5000000 、 Indirect expense:\1500000 )

    On the basis of phononic band analyses, several prototype structures of "acoustic diode" in which only unidirectional propagation is permitted, have been proposed and their experimental visualization have been performed. In addition, highly efficient acoustic wave guides based on topological edge mode have been demonstrated.
    The rectification characteristics of elastic wave based on the hetero-phononic structure, targeted at the beginning, were successfully achieved by optimizing interface structure. On the nonreciprocal acoustic waveguide by applying the external wave modulation, some attempts for the enhancement of modulation effects were examined and their efficiency improvement has been verified. In addition, in the topological acoustic wave guide, it succeeded in the demonstration of the high transmission characteristic beyond our expectation. It thus can become an essential key to the realization of “the phononic information processing system.”

    researchmap

  • Ultrasonics/Surface Acoustic-Wave Control and Energy-Transport/Harvesting Devices using Phononic Structures

    Grant number:25600132  2013.04 - 2015.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Exploratory Research

    TSURUTA Kenji, FUJIMORI Kazuhiro, ISHIKAWA Atsushi

      More details

    Grant amount:\3510000 ( Direct expense: \2700000 、 Indirect expense:\810000 )

    Periodic structure called “Phononic Crystal”, which enables tailoring of elastic wave propagation, has been designed for new energy-transport/harvesting devices and for new THz wave generation/control.
    Specifically, we have performed i) numerical design and proof-of-principle experiments of GRIN lenses consisting of a 2-dimensional phononic structure, ii) molecular-dynamics analysis of THz wave propagation on a piezoelectric thin film and its control by a periodic hole array, and iii) numerical design of an acoustic diode based on a piezoelectric-dielectric periodic structure.

    researchmap

  • Study of near-infrared surface-plasmon-resonance fiber sensor

    Grant number:24656257  2012.04 - 2014.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Exploratory Research

    FUKANO Hideki, TSURUTA Kenji, TAUE Syuji

      More details

    Grant amount:\4160000 ( Direct expense: \3200000 、 Indirect expense:\960000 )

    We have studied a super-high sensitivity fiber sensor by a new detection technique. A metallic thin film or metal nanoparticles have formed on the surface of silica fiber used for optical communication system. The free electrons of the metal surface are excited by the electric field of transmitting light, and then collective oscillation of electrons, called surface plasmon resonance occurs. This induces the phase shift of light. This shift has been detected using a multimode interference produced by the special fiber configuration. We clarified that the resonance wavelength of the light can be controlled by changing the metal structure.

    researchmap

  • Nano Materials Science for Atomic Scale Modification

    Grant number:19053003  2007 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Priority Areas

    IKUHARA Yuichi, YAMAMOTO Takahisa, MUTO Shunsuke, MORITA Seizo, TANAKA Isao, TSURUTA Kenji, TANIGUCHI Takashi, KITAOKA Satoshi

      More details

    Grant amount:\26600000 ( Direct expense: \26600000 )

    本終了研究では特定領域の成果報告会や国際会議を企画し,本特定領域によって構築された「機能元素の学理」の効果的な普及を行った.さらに,本特定領域で得られた知見を次代を担う若手研究者に引き継ぐためのプログラム(若手研究者向けセミナー,若手研究者海外滞在)も企画・運営した.また,班内の効果的な情報共有・打ち合わせのためのインターネット会議の実施や情報管理も本総括班が行った.
    平成24年度では以下のような総括班会議,成果報告会,シンポジウム等を行い,本特定領域で得られた研究成果の発信を行ってきた.
    ・総括班会議の開催6月(東京)
    ・特定領域最終成果報告会(公開)6/8(東京)【産官学から約200名の参加があった】
    ・国際会議の開催(公開)5/9-11(岐阜)【国内外から約300名の参加があった】
    The 3rd International Symposium on Advanced Microscopy and Theoretical Calculations(AMTC3)
    ・国際学術雑誌企画5月(AMTC Letters No.3)
    ・最終研究成果ニュースレター冊子体の企画6月
    ・特定領域特集号発刊(セラミックス)
    ・若手研究者向けセミナー1月(名古屋)
    6月に開催した本特定領域の最終成果報告会においては200名近い参加があり,非常に盛会であった.また,5月に行われた国際会議においても世界中から第一線で活躍する研究者が一堂に会し,3日間にわたって活発な議論が行われた.また,次世代研究者の育成をめざし,研究者の海外滞在プログラム(米国オークリッジ国立研究所,英国インペリアルカレッジ)も行われた.また大学院生を対象とした第一原理計算,透過型電子顕微鏡,電子分光に関するセミナーも開催した.

    researchmap

  • Nanodopant Analysis via Multiscale Numerical Method

    Grant number:19053007  2007 - 2011

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Priority Areas

    TSURUTA Kenji, KOYAMA Toshiyuki, OGATA Shuji, HYODO Shiaki

      More details

    Grant amount:\33900000 ( Direct expense: \33900000 )

    Novel methodologies/algorithms, which connect two or more physical scales, have been developed for the materials simulation as a tool to extract fundamental principles in materials science of functional elements. Also, through collaboration with a nanoscale measurement group and a process group in the project, the above-mentioned new techniques have been applied to quantitative elucidation of atomic/electronic structures of a dislocation and electronic states and stability of a segregated atom in alumina ceramic, which is adopted as a common sample in the project, and the effectiveness of the methods has been proved.

    researchmap

  • Strongly correlated quantum phase associated with charge fluctuation

    Grant number:18002008  2006 - 2010

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Specially Promoted Research

    GOTO Terutaka, NEMOTO Yuichi, KITAZAWA Hideaki, SUZUKI Hiroyuki, KANETA Hiroshi, YANAGISAWA Tatsuya, IYETOMI Hiroshi, ONO Yoshiaki, TAKEDA Naoya, TSURUTA Kenji, SAKAI Osamu, AKATSU Mitsuhiro, ISHII Isamu, MITSUMOTO Keisuke

      More details

    Grant amount:\284440000 ( Direct expense: \218800000 、 Indirect expense:\65640000 )

    The ultrasonic strains have specified symmetries and couple to the electric quadrupoles of the electronic and ionic quantum states. The ultrasonic measurements of the elastic constants and attenuation coefficients, therefore, may determine the quadrupole susceptibility. In the present projects, using low-temperature ultrasonic phase difference measurement apparatus with a highly velocity resolution, we have carried out a study of non-Kramers doublet of localized 4f-electron in rare-earth compounds, rattling of local oscillator in clathrate compounds, vacancy orbital in boron-doped silicon crystal in pursuing strongly correlated quantum phases associated with charge fluctuation.

    researchmap

  • Multiscale Design of Nanostructured Ceramics for High-frequency Electromagnetic Applications

    Grant number:17560597  2005 - 2007

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    TSURUTA Kenji, TOTSUJI Chieko, TOTSUJI Hiroo, KISHIMOTO Akira

      More details

    Grant amount:\3670000 ( Direct expense: \3400000 、 Indirect expense:\270000 )

    In this research, we have developed novel and highly accurate simulation methodologies for nanostructured materials that are used in ultra high-speed mass communication devices. We have applied the methods to clarify the effects of defects, grain boundaries, and impurities on electronic and magnetic properties of nanostructured ceramics and semiconductors.
    During the research term, we have obtained the following outcomes:
    1. The electronic transportation coefficient in Si nanowires has been calculated via the time-dependent Schrodinger equation based on the tight-binding approximation;
    2. The diffusion processes of the impurity hydrogen in a Si crystal and grain boundary were analyzed by hybrid quantum/classics molecular dynamics method. We have found possible mechanism of the sudden drop of activation energy of H atom around and above 1000K due to the interactions between the defects and the impurity.
    3. We have found the possibility that the residual magnetization of diamond is locally generated when Ni impurities were inserted at interstitial sites.
    4. The spin polarizability in low-dimensional electron system was evaluated through the correlations between electrons trapped in low-dimensional system by the classics map method.
    5. The structural and normal-mode analyses were performed to investigate the relationship between melting processes and the vibrational modes.
    6. The finite-difference time-domain (FDTD) simulation methodologies for electromagnetic responses of meta-materials were developed and applied to the metal-insulator multilayer structures.
    We have presented these results in a lot of domestic societies meetings and in four invited lectures.

    researchmap

  • 並列分子動力学/電子状態計算手法によるナノ構造セラミックスの粒界形成・機能制御

    Grant number:14750554  2002 - 2004

    日本学術振興会  科学研究費助成事業  若手研究(B)

    鶴田 健二

      More details

    Grant amount:\3400000 ( Direct expense: \3400000 )

    本研究では、申請者がこれまで蓄積してきた研究成果を踏まえた上で、更なる発展を目指し、下記のような達成目標を掲げてきた:
    (a)粒界不純物拡散機構に対する分子動力学/電子状態解析;
    (b)ナノ構造中の電子伝導の解析;
    (c)超長時間シミュレーション手法の確立とナノ粒子成長・粒界移動解析への適用。
    最終年度である本年度では、下記の成果により上記目標のほとんどが達成された。
    (1)計算グリッド上での高効率な計算を可能にするO(N)並列TBMDおよびハイブリッド並列TBMD/MDコードを完成させた。
    (2)上記のO(N)並列TBMDおよびハイブリッド並列TBMD/MD法により、Si結晶・粒界中の水素拡散に関するマルチスケールシミュレーションを実施し、高温におけるSi結晶・粒界付近での水素拡散のメカニズムを解析した。
    (3)前年度から引き続いて、古典MDとTBMDとの併用、ならびに上記のハイブリッドTBMD/MD手法を用いて、SiおよびSiC結晶粒界の高温における構造安定性の解析を行った。また、Si粒界における電子状態の局在性を、電子密度行列の空間的広がりから解析し、ボンドの乱れとs軌道成分の増大との関係を定量的に明らかにした。
    (4)Si結晶中の不活性原子のTBMDシミュレーションを実施し、安定位置、拡散経路ならびに活性化エネルギーの見積もりを行った。
    (5)多項式展開法による時間依存シュレディンガー方程式の高速計算法を開発し、鎖状ナノ構造Si中の電子伝導ダイナミックスの解析を行った。
    (6)超長時間シミュレーションを可能にする確率的差分方程式法を密度汎関数分子動力学シミュレーションへ適用し、その有用性と数値的安定性を検証した。

    researchmap

  • Studies on the Origin of Superionicity by parallel Computing---Basic Research for New Materials with High Ionic Conductivity---

    Grant number:12440085  2000 - 2002

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    KOBAYASHI Michisuke, TSURUTA Kenji, KUSAKABE Koichi, IYETOMI Hiroshi

      More details

    Grant amount:\8400000 ( Direct expense: \8400000 )

    【0!□】First the connection and the operation check of parallel computers system have been arranged with the help of Dr. H. Kikuchi (LSU, USA), Prof. A. Nakano (foreign collaborator, SCU, USA).
    【1!□】 (1) The tight-band electronic band calculations and DV-Xα cluster method of β-Ag3SX (X=I, Br) have been carried out to study the p-d hybridization and the superionicity. (2) A computer simulation by a molecular dynamics method at constant volume has been performed to a model material which is composed of accumulating two different fluorite conductors : ・・・CaF_2-BaF_2-CaF_2-BaF_2・・・. It has been obtained that the diffusion coefficient and ionic conductivity of F ions in the layered fluorite conductors increases with decreasing periods.
    【2!□】 (1) The sintering process for nano-particles of TiO_2 have been carried out by MD simulation. Internal structure and space-charge distribution have been studied in the nano-phase. (2) Dynamical properties of a binary Coulomb compound have been also investigated.
    【3!□】 Using the tight binding molecular dynamics (TBMD) which has been developed by authors, the following things have been studied : (1) Structure of grain boundary in diamond crystal and its effect due to hydrogen addition. (2) The study of diffusion path of hydrogens in both Si and amorphous Si.
    【4!□】 By performing the project, many important results have been obtained. Those resuts have been published on joumals and presented in conferences. Studies are further developing. Exciting progress in our project will be expected.

    researchmap

  • セラミックス基ナノ構造体の電子機能制御:量子・古典並列分子動力学計算

    Grant number:12750604  2000 - 2001

    日本学術振興会  科学研究費助成事業  奨励研究(A)

    鶴田 健二

      More details

    Grant amount:\2400000 ( Direct expense: \2400000 )

    本研究の目的は、セラミックス基ナノ構造体における新しい電子機能の発現について、その物性解析に対する量子・古典分子動力学シミュレーションの実践的適用である。本年度に遂行を計画した課題は:(1)タイトバインディング法および分子動力学法に基づくナノ構造セラミックスにおける原子・電子輸送係数の計算;(2)第一原理計算コードの整備とタイトバインディング(TB)分子動力学(MD)計算用のパラメータ抽出方法検討;および(3)それらの成果発表であった。
    計画(1):高温・高圧下でのSiCやTiO_2のナノ微粒子間のネック形成・焼結のシミュレーションを実施(雑誌論文1、2、3、5番目参照)。また、古典MD計算や中性子散乱実験データと比較し、粒界イオン拡散の温度依存性について、その微視的なメカニズムを解明した(雑誌論文1、5番目参照)。また、微粒子間粒界での電子移動度についてのTB計算も行い、セラミックス対応粒界において電子移動度が増大する可能性を提唱した(雑誌諭文1番目参照)。また、これらのシミュレーションにおいて、微粒子がそれぞれの結晶方位を自己組織形成的に揃え合う現象を見い出し、高緻密化と機能性制御へ向けた重要な知見を得た(雑誌諭文2、5番目参照)。
    計画(2):昨年試みた平面波基底計算からのTBパラメータ抽出に続き、第一原理LMTO計算法からの抽出法と精度についての検討を行った。
    計画(3):上記成果を国内外の学会で報告した。(日本物理学会・日本金属学会・日本セラミックス協会の各秋期大会、日本MRS学術シンポジウム)特に日本物理学会秋期分科会において、大規模シミュレーションに関するシンポジウム招待講演を行い、本研究の遂行状況と他の手法等の現状を解説した。また、日本MRSのシンポジウム「多粒子集合体の組織形成ダイナミックス」を組織・開催し、当該研究に関連する分野の多くの研究者間の交流をはかった。また、3月末に開かれる日本セラミックス協会の春期大会でも、当該研究の成果発表を行った。

    researchmap

  • Large Scale Quantum Simulations Plasmas

    Grant number:11480110  1999 - 2001

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    TOTSUJI Hiroo, TOTSUJI Chieko, TSURUTA Kenji

      More details

    Grant amount:\5900000 ( Direct expense: \5900000 )

    In principle, electrons in plasmas are quantum objects. Except for the cases at high temperatures and with low densities where the quantum nature of electrons does not play an important role, we need to take it into account. One of typical examples is the implosion process in the inertial confinement fusion where ions and elecrons are strongly coupled.
    The lack of long-range order of crystalline lattice makes theoretical treatment of quantum plasmas difficult and numerical simulations become an important method of analysis. The quantum simulation usually requires large computational resources and the applicable system size is limited. In addition to this, we have another difficulty coming from the long-range nature of the Coulomb interaction. The purpose of this research project is to find solutions for these problems.
    We have applied the density functional molecular dynamics (DFMD) to overcome the first point in 2. In this method, the electron density is regard ed as a dynamic variable and one can perform large scale quantum simulations. We have analyzed the hydrogen plasma in the domain of liquid metal and have shown that quantum simulations with 1000 electrons are affordable. We have also confirmed that, by employing parallel PC clusters, we can simulate systems larger than the latter by one or two orders of magnitude. We have also checked the accuracy of DFMD by comparing the results with those of first principle simulations.
    To solve the second problem in 2, we have developed the computation code on the basis of the Fast Multipole method(FMM). We have applied our code to Coulomb clusters and found the critical system size for its structural phase transition. We have also applied our code to the Yukawa system which can be regarded as the simplest approximation for ions in quantum plasmas. The Yukawa system serves as a model of dusty plasmas whose behavior is an important subject in relation to plasma processing. Applications to Yukawa systems provide us with not only a reference system but also useful results for real systems.

    researchmap

  • Large Scale Simulations of Fusion Plasmas

    Grant number:08458109  1996 - 1998

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    TOTSUJI Hiroo, TOTSUJI Chieko, ISHII Tadao, TSURUTA Kenji

      More details

    Grant amount:\5600000 ( Direct expense: \5600000 )

    1. Methods of numerical simulations have been developed for strongly interacting plasmas realized in the process of implosion of fuel targets in the inertial confinement fusion. For such plasmas, numerical simulations are indispensable in analyzing their various properties.
    2. For systems with inhomogeneity and interfaces, large scale simulations are required and are possible only by the parallel computation with many CPUs due to limitations on the speed of a single CPU.In this project, a parallel PC cluster has been used.
    3. For the classical ion system which forms the basis of the large scale simulations of plasmas, we have developed the constant temperature and constant-pressure or constant-volume molecular dynamics. We have applied the method to the Yukawa system and the Yukawa mixture, the system of ions interacting via the Coulomb potential screened by electrons, and obtained their phase diagram in external fields. We have also realized the code for the fast multiploe method which is very efficient for large scale Coulomb systems. As a result, we are able to simulate more than 100000 particles.
    4. For quantum simulations of plasmas including electrons, we have applied the density functional molecular dynamics. In this method, the electron density is regarded as a dynamic variable and one can perform large scale quantum simulations. We have analyzed the hydrogen plasma in the domain of liquid metal and have shown that quantum simulations with 1000 electrons are affordable. When we approach the line of the pressure ionization from high densities, we observe clearly the decrease of the degree of ionization and the increase of the electronic screening of ions by visualizing the distribution of electrons. We have also developed the ab initio molecular dynamics in. order to compare the results with those of the density functional molecular dynamics and guide the application of the latter.

    researchmap

▼display all

 

Class subject in charge

  • Seminar in Multiscale Device Design (2023academic year) Other  - その他

  • Seminar in Multiscale Device Design (2023academic year) Year-round  - その他

  • Seminar in Multiscale Device Design (2023academic year) Year-round  - その他

  • Multiscale Numerical Analysis (2023academic year) Late  - その他

  • Multiscale Numerical Analysis (2023academic year) Late  - その他

  • Advanced semicondoctor technology (2023academic year) Late  - 木7~8

  • Numerical Computations (2023academic year) Third semester  - 月3~4,木1~2

  • Functional Materials and Devices (2023academic year) Prophase  - その他

  • Functional Materials and Devices (2023academic year) Prophase  - その他

  • Advanced Study (2023academic year) Other  - その他

  • Technical Writing(Electronic Engineering) (2023academic year) Prophase  - その他

  • Technical Presentation(Electronic Engineering) (2023academic year) Late  - その他

  • Technical Writing (2023academic year) Prophase  - その他

  • Technical Presentation (2023academic year) Late  - その他

  • Advanced Electronic Devices (2023academic year) Prophase  - 月7~8

  • Advanced Electronic Devices (2023academic year) Prophase  - 月7~8

  • Specific Research of Electronics and Information Systems Engineering (2023academic year) Year-round  - その他

  • Elementary Condensed-matter Physics (2023academic year) 1st semester  - 火7~8,金3~4

  • Elementary Condensed-matter Physics (2023academic year) 1st semester  - 火7~8,金3~4

  • (L15)Device Physics (2023academic year) special  - その他

  • (T10)Advanced Device Physics (2023academic year) special  - その他

  • Seminar in Multiscale Device Design (2022academic year) Year-round  - その他

  • Multiscale Numerical Analysis (2022academic year) Late  - その他

  • Differential Equation (2022academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation (2022academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation 1 (2022academic year) Third semester  - 火3~4

  • Differential Equation 2 (2022academic year) Fourth semester  - 火3~4

  • Numerical Computations (2022academic year) Third semester  - 月3~4,木1~2

  • Functional Materials and Devices (2022academic year) Prophase  - その他

  • Technical Writing (2022academic year) Prophase  - その他

  • Technical Presentation (2022academic year) Late  - その他

  • Advanced Electronic Devices (2022academic year) Prophase  - 月7,月8

  • Specific Research of Electronics and Information Systems Engineering (2022academic year) Year-round  - その他

  • Elementary Condensed-matter Physics (2022academic year) 1st semester  - その他

  • Seminar in Multiscale Device Design (2021academic year) Year-round  - その他

  • Multiscale Numerical Analysis (2021academic year) Late  - その他

  • Differential Equation (2021academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2021academic year) 3rd and 4th semester  - [第3学期]火3,火4, [第4学期]火3~4

  • Differential Equation (2021academic year) 3rd and 4th semester  - [第3学期]火3,火4, [第4学期]火3~4

  • Differential Equation 1 (2021academic year) Third semester  - 火3,火4

  • Differential Equation 2 (2021academic year) Fourth semester  - 火3,火4

  • Functional Materials and Devices (2021academic year) Prophase  - その他

  • Technical Writing (2021academic year) Prophase  - その他

  • Technical Presentation (2021academic year) Late  - その他

  • Advanced Electronic Devices (2021academic year) Prophase  - 月7,月8

  • Specific Research of Electronics and Information Systems Engineering (2021academic year) Year-round  - その他

  • Elementary Condensed-matter Physics (2021academic year) 1st semester  - 月5,月6,木7,木8

  • Elementary Condensed-matter Physics (2021academic year) 1st semester  - 月5~6,木7~8

  • Electronic Theory of Condensed Matter Engineering I (2021academic year) 1st semester  - 月5,月6,木7,木8

  • Seminar in Multiscale Device Design (2020academic year) Prophase

  • Seminar in Multiscale Device Design (2020academic year) Year-round  - その他

  • Seminar in Multiscale Device Design (2020academic year) Other  - その他

  • Multiscale Numerical Analysis (2020academic year) Late  - その他

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2020academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 1 (2020academic year) Third semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Differential Equation 2 (2020academic year) Fourth semester  - 火3,火4

  • Functional Materials and Devices (2020academic year) Prophase  - その他

  • Technical Writing (2020academic year) Prophase  - その他

  • Technical Presentation (2020academic year) Late  - その他

  • Advanced Electronic Devices (2020academic year) Prophase  - 月7,月8

  • Specific Research of Electronics and Information Systems Engineering (2020academic year) Year-round  - その他

  • Elementary Condensed-matter Physics (2020academic year) 1st semester  - 月5,月6,木7,木8

  • Elementary Condensed-matter Physics (2020academic year) 1st semester  - 月5,月6,木7,木8

  • Electronic Theory of Condensed Matter Engineering I (2020academic year) 1st semester  - 月5,月6,木7,木8

▼display all

 

Social Activities

  • JST さくらサイエンス 事業

    Role(s):Lecturer, Planner

    岡山大学大学院自然科学研究科  先端電子材料・デバイス設計技術体験  2020.2.17 - 2020.2.23