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 Physical Society (APS)  

DOI： 10.1103/physrevb.111.184515

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その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.111.184515/fulltext

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 Physical Society (APS)  

DOI： 10.1103/physrevb.111.144508

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その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.111.144508/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

Abstract

Acoustic metasurfaces, which utilize acoustically resonating structures, enable precise control and shielding of sound waves through compact, subwavelength devices. In this study, we propose a multi-resonant metasurface design comprising a decorated membrane, Helmholtz resonators, and a defective pillar array. The proposed structure facilitates both sound absorption and energy harvesting. The effectiveness of its multiple-resonance mechanism was validated through numerical and experimental analyses. Numerical calculations revealed three resonant peaks within the frequency range of 500 Hz to 4000 Hz, achieving an average absorption coefficient of over 90%. Additionally, the structure demonstrated an average generated voltage of 1.6 mV as the potential difference across the PZT patch. Furthermore, we propose the application of this structure in the development of phononic-structural metasurfaces. This metasurface comprises multiple resonant structures of varying sizes, enabling the superposition of resonance peaks from individual units. This design facilitates broadband sound absorption in the audible frequency range.

DOI： 10.35848/1347-4065/adbd4a

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その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/adbd4a/pdf

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：American Physical Society (APS)  

DOI： 10.1103/physrevb.111.064502

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その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.111.064502/fulltext

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Supercurrent diodes are nonreciprocal electronic elements whose switching current depends on their flow direction. Recently, a variety of composite systems combining different materials and engineered asymmetric superconducting devices have been proposed. Yet, ease of fabrication and tunable sign of supercurrent rectification joined to large efficiency have not been assessed in a single platform so far. We demonstrate that all-metallic superconducting Dayem nanobridges naturally exhibit nonreciprocal supercurrents under an external magnetic field, with a rectification efficiency up to ~ 27%. Our niobium nanostructures are tailored so that the diode polarity can be tuned by varying the amplitude of an out-of-plane magnetic field or the temperature in a regime without magnetic screening. We show that sign reversal of the diode effect may arise from the high-harmonic content of the current phase relation in combination with vortex phase windings present in the bridge or an anomalous phase shift compatible with anisotropic spin-orbit interactions.

DOI： 10.1038/s42005-023-01458-9

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その他リンク： https://www.nature.com/articles/s42005-023-01458-9

開催年月日： 2025年6月25日 - 2025年6月27日

記述言語：日本語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2025年3月18日 - 2025年3月21日

記述言語：日本語   会議種別：口頭発表（一般）  

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開催年月日： 2025年3月18日 - 2025年3月21日

記述言語：日本語   会議種別：口頭発表（一般）  

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