研究者詳細 - 宮本　祐樹

Measurement of cesium 8 PJ2→6 PJ′2 electric quadrupole transition probabilities using fluorescence spectroscopy 査読

Jing Wang, Yuki Miyamoto, Hideaki Hara, Minoru Tanaka, Motomichi Tashiro, Noboru Sasao

Physical Review A 110 ( 1 ) 2024年7月

Analysis on high-resolution spectrum of the S1–S0 transition of free-base phthalocyanine 査読

Yuki Miyamoto, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Katsunari Enomoto, Naofumi Nakayama, Masaaki Baba

The Journal of Chemical Physics 2024年4月

Newly observed low-lying Ω = 1 state of PbO 査読

Katsunari Enomoto, Taichi Tojo, Kaori Kobayashi, Susumu Kuma, Ayami Hiramoto, Yuki Miyamoto, Masaaki Baba

The Journal of Chemical Physics 2024年4月

Periodic superradiance in an Er:YSO crystal 査読

Hideaki Hara, Junseok Han, Yasutaka Imai, Noboru Sasao, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura, Yuki Miyamoto

Physical Review Research 2024年1月

Doppler-free Spectroscopy of Buffer-Gas-Cooled Calcium Monohydroxide 査読

Yuki Miyamoto, Reo Tobaru, Yuiki Takahashi, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Katsunari Enomoto, Masaaki Baba

The Journal of Physical Chemistry A 127 ( 21 ) 4758 - 4763 2023年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

In this study, we report the Doppler-free spectra ofbuffer-gas-cooledCaOH. We observed five Doppler-free spectra containing low-J Q(1) and R-12 transitions, which wereonly partially resolved by previous Doppler-limited spectroscopies.The spectra frequencies were corrected using the Doppler-free spectraof iodine molecules; accordingly, the uncertainty was estimated tobe below 10 MHz. We determined the spin-rotation constant inthe ground state, which agrees with the values reported in the literatureobtained based on millimeter-wave data within 1 MHz. This suggeststhat the relative uncertainty is much smaller. The present study demonstratesthe Doppler-free spectroscopy of a polyatomic radical and the broadapplicability of the buffer gas cooling method to molecular spectroscopy.CaOH is the only polyatomic molecule that can be directly laser-cooledand trapped in a magneto-optical trap. High-resolution spectroscopyof such molecules is useful for establishing efficient laser coolingschemes of polyatomic molecules.

DOI： 10.1021/acs.jpca.2c08565

Measurement of Doppler effects in a cryogenic buffer-gas cell 査読

Ayami Hiramoto, Masaaki Baba, Katsunari Enomoto, Kana Iwakuni, Susumu Kuma, Yuiki Takahashi, Reo Tobaru, Yuki Miyamoto

Physical Review A 107 ( 4 ) 2023年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYSICAL SOC

Buffer-gas cooling is a universal cooling technique for molecules and used for various purposes. One of its ap- plications is using molecules inside a buffer-gas cell for low-temperature spectroscopy. Although a high-intensity signal is expected in the cell, complex molecular dynamics is a drawback for precise spectroscopy. In this study, we performed high-resolution absorption spectroscopy of low -J transitions in the A similar to 2 pi(0, 0, 0)-X similar to 2E+(0, 0, 0) band of calcium monohydroxide (CaOH). CaOH molecules were produced by laser ablation in a copper cell and cooled to similar to 5 K using helium buffer gas. We probed the Doppler effects in a buffer-gas cell by injecting counterpropagating lasers inside the cell. The time evolutions of the Doppler width and shift were simulated using a dedicated Monte Carlo simulation and compared with data.

DOI： 10.1103/PhysRevA.107.043114

High-resolution spectroscopy of buffer-gas-cooled phthalocyanine

Yuki Miyamoto, Reo Tobaru, Yuiki Takahashi, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Katsunari Enomoto, Masaaki Baba

Communications Chemistry 5 ( 1 ) 2022年12月

担当区分：筆頭著者,　責任著者掲載種別：研究論文（学術雑誌）

For over five decades, studies in the field of chemical physics and physical chemistry have primarily aimed to understand the quantum properties of molecules. However, high-resolution rovibronic spectroscopy has been limited to relatively small and simple systems because translationally and rotationally cold samples have not been prepared in sufficiently large quantities for large and complex systems. In this study, we present high-resolution rovibronic spectroscopy results for large gas-phase molecules, namely, free-base phthalocya-nine (FBPc). The findings suggest that buffer-gas cooling may be effective for large molecules introduced via laser ablation. High-resolution electronic spectroscopy, combined with other experimental and theoretical studies, will be useful in understanding the quantum properties of molecules. These findings also serve as a guide for quantum chemical calculations of large molecules.

DOI： 10.1038/s42004-022-00783-4

High-resolution spectroscopy of the X 0⁺→ A0⁺, C0⁺ transitions of PbO in 22 300–25 100 cm^-1 査読

Katsunari Enomoto, Ai Nakano, Takehiro Suzuki, Kaori Kobayashi, Yuiki Takahashi, Yuki Miyamoto, Masaaki Baba

Journal of Molecular Spectroscopy 390 2022年11月

掲載種別：研究論文（学術雑誌）

High-resolution excitation spectra of the X0+→ A0+ and X0+→ C0+ transitions of lead monoxide (PbO) are observed in a range of 22 300-25 100 cm−1. Transition frequencies are determined with an average uncertainty of 8.5×10−4 cm−1 by comparing with resonances of an ultralow expansion etalon. PbO molecules are produced by laser ablation in a cold helium buffer gas, which provides rotationally cold but vibrationally hot molecules and allows observation of hot bands of excitation from the υ′′=1,2 vibrational states. Spectroscopic constants and potential curves for the A0+ and C0+ states are determined, and the spectroscopic constants obtained for the three main isotopologues are reproduced to a satisfactory level using a single potential curve for each electronic state. This indicates that perturbation due to other electronic states is negligibly small.

DOI： 10.1016/j.jms.2022.111713

Low-J Transitions in A˜2Π(0,0,0)−X˜2Σ+(0,0,0) Band of Buffer-gas-cooled CaOH 査読

Yuiki Takahashi, Masaaki Baba, Katsunari Enomoto, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Reo Tobaru, Yuki Miyamoto

The Astrophysical Journal 936 ( 2 ) 97 - 97 2022年9月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Astronomical Society

Abstract

Calcium monohydroxide radical (CaOH) is receiving an increasing amount of attention from the astrophysics community as it is expected to be present in the atmospheres of hot rocky super-Earth exoplanets as well as interstellar and circumstellar environments. Here, we report the high-resolution laboratory absorption spectroscopy on low-J transitions in ${\tilde{A } }^{2}{\rm{\Pi } }(0,0,0)-{\tilde{X } }^{2}{ { \rm{\Sigma } } }^{+}(0,0,0)$ band of buffer-gas-cooled CaOH. In total, 40 transitions out of the low-J states were assigned, including 27 transitions that have not been reported in previous literature. The determined rotational constants for both ground and excited states are in excellent agreement with previous literature, and the measurement uncertainty for the absolute transition frequencies was improved by more than a factor of 3. This will aid future interstellar, circumstellar, and atmospheric identifications of CaOH. The buffer-gas-cooling method employed here is a particularly powerful method to probe low-J transitions and is easily applicable to other astrophysical molecules.

DOI： 10.3847/1538-4357/ac87fb

Simulation Study of Laser Ionization of Muonium by 1S-2S Excitation for the Muon g − 2/EDM Experiment at J-PARC

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ac87fb/pdf

Ce Zhang, Hideaki Hara, Takahiro Hiraki, Yutaka Ikedo, Yasutaka Imai, Katsuhiko Ishida, Saeid Kamal, Naritoshi Kawamura, Akihiro Koda, Yajun Mao, Takahiko Masuda, Tsutomu Mibe, Yasuhiro Miyake, Yuki Miyamoto, Yu Oishi, Masashi Otani, Patrick Strasser, Koichiro Shimomura, Kazuhito Suzuki, Satoshi Uetake, Takayuki Yamazaki, Shinsuke Yamamoto, Koji Yoshimura, Mitsuhiro Yoshida

Proceedings of the 3rd J-PARC Symposium (J-PARC2019) 2021年3月

Absolute X-ray energy measurement using a high-accuracy angle encoder 査読

Takahiko Masuda, Tsukasa Watanabe, Kjeld Beeks, Hiroyuki Fujimoto, Takahiro Hiraki, Hiroyuki Kaino, Shinji Kitao, Yuki Miyamoto, Koichi Okai, Noboru Sasao, Makoto Seto, Thorsten Schumm, Yudai Shigekawa, Kenji Tamasaku, Satoshi Uetake, Atsushi Yamaguchi, Yoshitaka Yoda, Akihiro Yoshimi, Koji Yoshimura

Journal of Synchrotron Radiation 28 ( 1 ) 111 - 119 2021年1月

掲載種別：研究論文（学術雑誌）出版者・発行元：International Union of Crystallography (IUCr)

This paper presents an absolute X-ray photon energy measurement method that uses a Bond diffractometer. The proposed system enables the prompt and rapid <italic>in situ</italic> measurement of photon energies over a wide energy range. The diffractometer uses a reference silicon single-crystal plate and a highly accurate angle encoder called SelfA. The performance of the system is evaluated by repeatedly measuring the energy of the first excited state of the potassium-40 nuclide. The excitation energy is determined as 29829.39 (6) eV, and this is one order of magnitude more accurate than the previous measurement. The estimated uncertainty of the photon energy measurement was 0.7 p.p.m. as a standard deviation and the maximum observed deviation was 2 p.p.m.

DOI： 10.1107/s1600577520014526

Geometry-dependent spectra and coherent-transient measurement of nearly degenerate four-wave mixing using two-photon resonance 査読

Hideaki Hara, Yuki Miyamoto, Takahiro Hiraki, Kei Imamura, Takahiko Masuda, Noboru Sasao, Satoshi Uetake, Akihiro Yoshimi, Koji Yoshimura, Motohiko Yoshimura

Journal of Physics B: Atomic, Molecular and Optical Physics 52 ( 23 ) 235402 2019年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：{IOP} Publishing

We study nearly degenerate four-wave mixing using a two-photon-allowed vibrational transition of parahydrogen. A signal photon is generated by a trigger photon and coherence among parahydrogen, which is prepared by two counterpropagating pump pulses, and we investigate the dependence of the signal pulse energy on the trigger frequency. The measured spectra depend on the geometry, shifting depending on the direction of the signal pulse and on the small angle formed by the counterpropagating pump pulses. Furthermore, we investigate the dependence of signal pulse energy on the incident time of the trigger pulse. The measured signal pulse energy is high if the trigger pulse is delayed slightly with respect to the pump pulses. We demonstrate that these geometry-dependent spectra and coherent-transient response can be explained by using simple models.

DOI： 10.1088/1361-6455/ab4a6e

Coherent two-photon emission from hydrogen molecules excited by counter-propagating laser pulses 査読

X-ray pumping of the 229Th nuclear clock isomer 査読

Takahiko Masuda, Akihiro Yoshimi, Akira Fujieda, Hiroyuki Fujimoto, Hiromitsu Haba, Hideaki Hara, Takahiro Hiraki, Hiroyuki Kaino, Yoshitaka Kasamatsu, Shinji Kitao, Kenji Konashi, Yuki Miyamoto, Koichi Okai, Sho Okubo, Noboru Sasao, Makoto Seto, Thorsten Schumm, Yudai Shigekawa, Kenta Suzuki, Simon Stellmer, Kenji Tamasaku, Satoshi Uetake, Makoto Watanabe, Tsukasa Watanabe, Yuki Yasuda, Atsushi Yamaguchi, Yoshitaka Yoda, Takuya Yokokita, Motohiko Yoshimura, Koji Yoshimura

Nature 573 ( 7773 ) 238 - 242 2019年9月

Hiraki, T., Hara, H., Miyamoto, Y., Imamura, K., Masuda, T., Sasao, N., Uetake, S., Yoshimi, A., Yoshimura, K., Yoshimura, M.

Journal of Physics B: Atomic, Molecular and Optical Physics 52 ( 4 ) 045401 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：{IOP} Publishing

We observed two-photon emission (TPE) signal from the first vibrationally excited state of parahydrogen gas coherently excited by counter-propagating laser pulses. A single narrow-linewidth laser source has roles in the excitation of the parahydrogen molecules and the induction of the TPE process. We measured dependences of the signal energy on the detuning, target gas pressure, and input pulse energies. These results are qualitatively consistent with those obtained by numerical simulations based on Maxwell-Bloch equations with one spatial dimension and one temporal dimension. This study of the TPE process in the counterpropagating injection scheme is an important step toward neutrino mass spectroscopy.

DOI： 10.1088/1361-6455/aafbd0

Energy response of X-rays under high flux conditions using a thin APD for the energy range of 6–33 keV 査読

Masuda, T., Hiraki, T., Kaino, H., Kishimoto, S., Miyamoto, Y., Okai, K., Okubo, S., Ozaki, R., Sasao, N., Suzuki, K., Uetake, S., Yoshimi, A., Yoshimura, K.

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 913 72 - 77 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

This paper reports on the demonstration of a high-rate energy measurement technique using a thin depletion layer silicon avalanche photodiode (Si-APD). A dedicated amplitude-to-time converter is developed to realize simultaneous energy and timing measurement in a high rate condition. The energy response of the system is systematically studied by using monochromatic X-ray beam with an incident energy ranging from 6 to 33 keV. The obtained energy spectra contain clear peaks and tail distributions. The peak fraction monotonously decreases as the incident photon energy increases. This phenomenon can be explained by considering the distribution of the energy deposit in silicon, which is investigated by using a Monte Carlo simulation.

DOI： 10.1016/j.nima.2018.10.029

Vibrational excitation of hydrogen molecules by two-photon absorption and third-harmonic generation 査読

Miyamoto, Y., Hara, H., Hiraki, T., Masuda, T., Sasao, N., Uetake, S., Yoshimi, A., Yoshimura, K., Yoshimura, M.

Journal of Physics B: Atomic, Molecular and Optical Physics 51 ( 1 ) 2018年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：{IOP} Publishing

We report the coherent excitation of the vibrational state of hydrogen molecules by two-photon absorption and the resultant third-harmonic generation (THG). Parahydrogen molecules cooled by liquid nitrogen are irradiated by mid-infrared nanosecond pulses at 4.8 mu m with a nearly Fourier-transform-limited linewidth. The first excited vibrational state of parahydrogen is populated by two-photon absorption of the mid-infrared photons. Because of the narrow linewidth of the mid-infrared pulses, coherence between the ground and excited states is sufficient to induce higher-order processes. Near-infrared photons from the THG are observed at 1.6 mu m. The dependence of the intensity of the near-infrared radiation on mid-infrared pulse energy, target pressure, and cell length is determined. We used a simple formula for THG with consideration of realistic experimental conditions to explain the observed results.

DOI： 10.1088/1361-6455/aa9782