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YAMADA Akiyoshi
Graduate School of Science / Division of Physics
Assistant Professor

Researcher basic information

■ Research Keyword
  • 固体物理
  • Transport theory
  • 磁気抵抗
  • High magnetic field
  • 量子振動
  • ディラック電子
  • フェルミ面
  • semimetals
■ Research Areas
  • Natural sciences / Semiconductors, optical and atomic physics
  • Natural sciences / Mathematical physics and basic theory

Research activity information

■ Award
  • Jun. 2026 IOP Publishing, IOP Trusted Reviewer

  • Jul. 2025 Physical Review B, Physical Review B Editor’s suggestion, Non-Fermi liquid transport and strong mass enhancement near the nematic quantum critical point in FeSe$_x$Te$_{1-x}$ thin films

  • Mar. 2025 Journal of Physical Society of Japan, JPSJ 編集部注目論文, Insulating behavior in the quantum limit state of Bi$_{1−x}$Sb$_x$ (x $\sim$ 0.04) in the vicinity of semimetal–semiconductor transition

  • Dec. 2024 強磁場科学研究会「パルスマグネット１００周年」, 若手優秀発表賞, 高磁場下ラシュバ電子系における自由電子の顕在化とホール伝導度の符号反転

  • Dec. 2024 学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」, Silver prize, Pseudo-anomalous Hall effect in multi-valley systems

  • Nov. 2024 第 18 回 物性科学領域横断研究会 (領域合同研究会), 最優秀若手奨励賞, Quantum magneto-transport theory and field-induced crossover in Hall conductivity

  • Apr. 2024 学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」, Silver prize, High-field transport in three-dimensional Rashba electron systems

  • Dec. 2023 強磁場科学研究会, presenter award, Non-equilibrium to equilibrium crossover in the magneto-transport phenomena

  • Dec. 2023 Communications Materials (Springer Nature), Outstanding Referee: Communications Materials

■ Paper
  • Akiyoshi Yamada, Yuki Fuseya
    American Physical Society (APS), Jun. 2026, Physical Review B, 113(24) (24), English
    [Refereed]
    Scientific journal

  • Shuto Tago, Akiyoshi Yamada, Yuki Fuseya
    The Japan Society of Applied Physics, 2026, JJAP Conference Proceedings, 12, 011010 - 011010
    [Refereed]
    Scientific journal

  • Shuto Tago, Akiyoshi Yamada, Yuki Fuseya
    Abstract We theoretically investigate magnetoresistance (MR) in the extreme quantum limit (EQL), where the kinetic energy becomes significantly smaller than the cyclotron energy, using the Kubo formula with Green’s functions and the T-matrix approximation. We uncover a magnetic-field-induced crossover in the scattering rate: in the Born regime and in the unitarity limit. This crossover gives rise to distinct MR behaviors in the EQL, characterized by linear transverse MR ( ) and negative longitudinal MR ( ). This dichotomy implies insulating behavior when the magnetic field is perpendicular to the current, and metallic behavior when it is parallel. In the unitarity limit, we further derive a universal relation that enables direct experimental determination of the impurity density from ρ xx and ρ xy . Our results establish a quantum–classical correspondence that remains valid even in the EQL, provided that the field dependences of the scattering rate and quantum corrections are properly incorporated.
    IOP Publishing, Aug. 2025, Journal of Physics: Condensed Matter, 37(32) (32), 325701 - 325701, English
    [Refereed]
    Scientific journal

  • Yuki Sato, Soma Nagahama, Ilya Belopolski, Ryutaro Yoshimi, Minoru Kawamura, Atsushi Tsukazaki, Akiyoshi Yamada, Masashi Tokunaga, Naoya Kanazawa, Kei S. Takahashi, Yoshichika Ōnuki, Masashi Kawasaki, Yoshinori Tokura
    American Physical Society (APS), Jul. 2025, Physical Review B, 112(4) (4), English
    [Refereed]
    Scientific journal

  • Akiyoshi Yamada, Yuki Fuseya
    Abstract We demonstrate that the non-linear field dependence in the Hall effect, often indistinguishable from the anomalous Hall effect (AHE), can be realized entirely within the classical mechanism due to the Lorentz force by analyzing multi-valley models for semiconductors and semimetals. The non-linear component in the Hall resistivity , which is purely classical in origin and referred to here as the pseudo AHE, originates from carrier mobility anisotropy or the coexistence of different charges. Since is inversely proportional to the carrier difference between electrons and holes Δn, it exceeds its zero-field value near charge neutrality. As a practical example, we show that the magnitude of the classical non-linear Hall response in ZrTe5 is comparable to the experimental values, underscoring the importance of accounting for classical contributions before attributing non-linear Hall effects to quantum mechanisms.
    IOP Publishing, Jul. 2025, Journal of Physics: Condensed Matter, 37(29) (29), 295705 - 295705, English
    [Refereed]
    Scientific journal

  • Yuma Yamaguchi, Takuya Fujita, Yuto Kinoshita, Akiyoshi Yamada, Atsushi Miyake, Ryota Hiraoka, Tatsuma D. Matsuda, Ryo Ninohira, Ryosuke Kurihara, Hiroshi Yaguchi, Yuki Fuseya, Masashi Tokunaga
    Physical Society of Japan, Apr. 2025, Journal of the Physical Society of Japan, 94(4) (4), English
    [Refereed]
    Scientific journal

  • Akiyoshi Yamada, Yuki Fuseya
    Abstract The three-dimensional magneto-conductivity tensor was derived in a gauge invariant form based on the Kubo formula considering quantum effects under a magnetic field, such as the Landau quantization and quantum oscillations. We analytically demonstrated that the quantum formula of the magneto-conductivity can be obtained by adding a quantum oscillation factor to the classical formula. This result establishes the quantum–classical correspondence, which has long been missing in magnetotransport phenomena. Moreover, we found dissipative-to-dissipationless crossover in the Hall conductivity by paying special attention to the analytic properties of the thermal Green’s function. Finally, by calculating the magnetoresistance of semimetals, we identified a phase shift in quantum oscillation originating from the dissipationless transport predominant at high fields.
    IOP Publishing, Mar. 2024, Journal of Physics: Condensed Matter, 36(24) (24), 245702 - 245702, English
    [Refereed]
    Scientific journal

  • Yuhao Ye, Akiyoshi Yamada, Yuto Kinoshita, Jinhua Wang, Pan Nie, Liangcai Xu, Huakun Zuo, Masashi Tokunaga, Neil Harrison, Ross D. McDonald, Alexey V. Suslov, Arzhang Ardavan, Moon-Sun Nam, David LeBoeuf, Cyril Proust, Benoît Fauqué, Yuki Fuseya, Zengwei Zhu, Kamran Behnia
    Abstract Bulk bismuth has a complex Landau spectrum. The small effective masses and the large g-factors are anisotropic. The chemical potential drifts at high magnetic fields. Moreover, twin boundaries further complexify the interpretation of the data by producing extra anomalies in the extreme quantum limit. Here, we present a study of angle dependence of magnetoresistance up to 65 T in bismuth complemented with Nernst, ultrasound, and magneto-optic data. All observed anomalies can be explained in a single-particle picture of a sample consisting of two twinned crystals tilted by 108° and with two adjacent crystals keeping their own chemical potentials despite a shift between chemical potentials as large as 68 meV at 65 T. This implies an energy barrier between adjacent twinned crystals reminiscent of a metal- semiconductor Schottky barrier or a p-n junction. We argue that this barrier is built by accumulating charge carriers of opposite signs across a twin boundary.
    Springer Science and Business Media LLC, Jan. 2024, npj Quantum Materials, 9(1) (1), English
    [Refereed]
    Scientific journal

  • Akiyoshi Yamada, Yuki Fuseya
    American Physical Society (APS), May 2022, Physical Review B, 105(20) (20), English
    [Refereed]
    Scientific journal

  • Akiyoshi Yamada, Yuki Fuseya
    American Physical Society (APS), Mar. 2021, Physical Review B, 103(12) (12), English
    [Refereed]
    Scientific journal

■ MISC
■ Lectures, oral presentations, etc.
  • 三回対称性を持つプレナーホール効果の古典論
    山田 暉馨, 伏屋 雄紀
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第7回領域会議, Apr. 2026, Japanese
    Oral presentation

  • Quantum theory for the magneto-optical Kerr effect
    Taro Hirono, Akiyoshi Yamada, Yuki Fuseya
    Quest For The Non-Perturbative Magnetic Field Effects In The 1000-Tesla Magnetic Field Region, Dec. 2025, English
    Poster presentation

  • Magnetoresistance in the extreme quantum limit and scattering rate: Self-consistent method and crossover to the unitarity limit
    Shuto Tago, Akiyoshi Yamada, Yuki Fuseya
    Quest For The Non-Perturbative Magnetic Field Effects In The 1000-Tesla Magnetic Field Region, Dec. 2025, English
    Poster presentation

  • Pseudo-anomalous Hall effect
    Akiyoshi Yamada, Yuki Fuseya
    Quest For The Non-Perturbative Magnetic Field Effects In The 1000-Tesla Magnetic Field Region, Dec. 2025, English
    Poster presentation

  • Bi$_{1-x}$Sb$_x$におけるサイクロトロン共鳴測定 II
    竹端寛治, 今中康貴, 仁野平諒, 矢口宏, 山田暉馨, 伏屋雄紀, 木下雄斗, 徳永将史
    日本物理学会秋季大会，広島大学, Sep. 2025, Japanese
    Poster presentation

  • Quantum-classical correspondence and non-equilibrium to equilibrium crossover in galvanomagnetic effects
    Akiyoshi Yamada, Yuki Fuseya
    International Conference on Strongly Correlated Electron Systems 2025, Jul. 2025, English
    Oral presentation

  • 超量子極限における磁気抵抗：磁場誘起のユニタリティ極限へのクロスオーバー
    Shuto Tago, Akiyoshi Yamada, Yuki Fuseya
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第5回領域会議，東北大学金属物理学研究所，2025年6月20日, Jun. 2025, Japanese
    Poster presentation

  • Paschen-Back-like crossover in the magneto-transport phenomena
    Akiyoshi Yamada, Yuki Fuseya
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第5回領域会議，東北大学金属物理学研究所, Jun. 2025, Japanese
    Poster presentation

  • 強磁場中の電子状態と輸送現象
    山田 暉馨, 伏屋 雄紀
    第一回 若手研究者分野横断交流会 ---物性研究の現状と今後の展開---，新潟 越後, Mar. 2025, Japanese
    [Invited]
    Oral presentation

  • 超量子極限における磁気抵抗と量子−古典対応
    多湖崇人, 山田 暉馨, 伏屋 雄紀
    日本物理学会春季大会，オンライン開催, Mar. 2025, Japanese
    Oral presentation

  • 複数フェルミ面に起因する“擬”異常ホール効果
    山田 暉馨, 伏屋 雄紀
    日本物理学会春季大会，オンライン開催, Mar. 2025, Japanese
    Oral presentation

  • Extended nematic quantum criticality in FeSe$_x$Te$_{1-x}$
    Yuki Sato, Soma Nagahama, Ilya Belopolski, Ryotaro Yoshimi, Minoru Kawamura, Atsushi Tsukazaki, Akiyoshi Yamada, Masashi Tokunaga, Naoya Kanazawa, Kei. S. Takahashi, Yoshichika Ōnuki, Masashi Kawasaki, Yoshinori Tokura
    APS March Meeting, Mar. 2025, English
    Oral presentation

  • 高磁場下ラシュバ電子系における自由電子の顕在化とホール伝導度の符号反転
    山田 暉馨, 伏屋 雄紀
    強磁場科学研究会 （第19回強磁場フォーラム総会）「パルスマグネット100周年」，東京大学物性研究所, Dec. 2024, Japanese
    Poster presentation

  • Pseudo-anomalous Hall effect in multi-valley systems
    Akiyoshi Yamada, Yuki Fuseya
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第4回領域会議，伊豆山研修センター, Dec. 2024, Japanese
    Poster presentation

  • Quantum magneto-transport theory and field-induced crossover in Hall conductivity
    Akiyoshi Yamada, Yuki Fuseya
    第18回 物性科学領域横断研究会 (領域合同研究会)，神戸大学 100年記念館 六甲ホール, Nov. 2024, Japanese
    Poster presentation

  • Field-induced insulating state of BiSb alloys in the quantum limit states
    Yuma Yamaguchi, Takuya Fujita, Yuto Kinoshita, Akiyoshi Yamada, Atushi Miyake, Ryota Hiraoka, Tatsuma D. Matsuda, Ryo Ninohira, Ryosuke Kurihara, Hiroshi Yaguchi, Yuki Fuseya, Masashi Tokunaga
    The 13th International Conference on Research in High Magnetic Fields (RHMF2024), Jul. 2024, English
    Poster presentation

  • High-field study of spin-valley coupled Dirac fermion in layered polar metal Ba$_{1−x}$Sr$_x$MnBi$_2$
    Masaki Kondo, Hideaki Sakai, Akiyoshi Yamada, Yuto Kinoshita, Masashi Tokunaga, Motoi Kimata, Atsushi Miyake, Kazuto Akiba, Hiroshi Murakawa, Noriaki Hanasaki
    The 13th International Conference on Research in High Magnetic Fields (RHMF2024), Jul. 2024, English
    Poster presentation

  • Quantum-classical correspondence and non-equilibrium to equilibrium crossover in magneto-transport phenomena
    Akiyoshi Yamada, Yuki Fuseya
    The 13th International Conference on Research in High Magnetic Fields (RHMF2024), Jul. 2024, English
    Poster presentation

  • Impacts of chemical substitution on polar structure and spin-valley coupling in layered Dirac metal Ba$_{1−x}$Sr$_x$MnBi$_2$
    M. Kondo, H. Sakai, Akiyoshi Yamada, M. Kimata, M. Tokunaga, A. Miyake, Y., Kinoshita, K. Akiba, H. Murakawa, N. Hanasaki
    The 22nd International Conference on Magnetism (ICM2024), Jul. 2024, English
    Poster presentation

  • High-field transport in three-dimensional Rashba electron systems
    Akiyoshi Yamada, Yuki Fuseya
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第3回領域会議，京都大学桂キャンパス, Apr. 2024, Japanese
    Poster presentation

  • ３次元ラシュバ電子の強磁場輸送現象
    山田 暉馨, 伏屋 雄紀
    日本物理学会春季大会，オンライン開催, Mar. 2024, Japanese
    Oral presentation

  • FeSe$_x$ Te$_{1-x}$ thin films as a platform for exploring exotic superconducting states
    Yuki Sato, Soma Nagahama, Ilya Belopolski, Ryutaro Yoshimi, Minoru Kawamura, Atsushi Tsukazaki, Naoya Kanazawa, Akiyoshi Yamada, Masashi Tokunaga, Kei S. Takahashi, Masashi Kawasaki, Yoshinori Tokura
    APS March Meeting, Mar. 2024, English
    Oral presentation

  • Quantum-classical correspondence and dissipative to dissipationless crossover in magneto-transport phenomena
    Akiyoshi Yamada, Yuki Fuseya
    International Symposium on Quantum Electronics 2024, Feb. 2024, English
    Poster presentation

  • Non-equilibrium to equilibrium crossover in magneto-transport phenomena
    山田 暉馨, 伏屋 雄紀
    量子液晶領域会議 ，東京大学物性研究所, Dec. 2023, Japanese
    Poster presentation

  • Quantum transport theory at high magnetic fields
    Akiyoshi Yamada, Yuki Fuseya
    MPI-UBC-UTokyo Workshop, 東京大学物性研究所, Dec. 2023, English
    Poster presentation

  • Non-equilibrium to equilibrium crossover in the magneto-transport phenomena
    山田 暉馨, 伏屋 雄紀
    強磁場科学研究会「強磁場研究における次世代ネットワーク形成とサイエンスの新展開」，東北大学金属科学研究所, Dec. 2023, Japanese
    Oral presentation

  • Non-equilibrium to equilibrium crossover in transport phenomena at high magnetic field
    Akiyoshi Yamada, Yuki Fuseya
    学術変革領域研究（A）「１０００テスラ超強磁場による化学的カタストロフィー：非摂動磁場による化学結合の科学」第2回領域会議，電気通信大学, Dec. 2023, Japanese
    Poster presentation

  • MBE成長させたFe(Se,Te)薄膜の上部臨界磁場測定
    佐藤雄貴, 永濱壮真, Ilya Belopolski, 吉見龍太郎, 川村稔, 塚崎敦, 山田 暉馨, 徳永将史, 金澤直也, 高橋圭, 川崎雅司, 十倉好紀
    日本物理学会秋季大会，仙台, Sep. 2023, Japanese
    Oral presentation

  • Bi$_{1-x}$Sb$_x$におけるサイクロトロン共鳴測定
    竹端寛治, 今中康貴, 伏屋雄紀, 木下雄斗, 山田 暉馨, 徳永将史, 仁野平諒, 矢口宏
    日本物理学会秋季大会，仙台, Sep. 2023, Japanese
    Oral presentation

  • 層状ディラック電子系Ba$_{1-x}$Sr$_x$MnBi$_2$における極性構造とスピン・バレー結合状態の制御
    近藤雅起, 酒井英明, 山田 暉馨, 木俣基, 徳永将史, 三宅厚志, 木下雄斗, 村川寛, 花咲徳亮
    日本物理学会秋季大会，仙台, Sep. 2023, Japanese
    Oral presentation

  • Galvanomagnetic Effect of Dirac Electrons Based on the Kubo Formula
    Shuto Tago, Akiyoshi Yamada, Yuki Fuseya
    International Conference on Strongly Correlated Electron Systems 2023, Jul. 2023, English
    Poster presentation

  • Semiclassical origin of negative magnetoresistance and planar Hall effect in Weyl electron system
    Akiyoshi Yamada, Yuki Fuseya
    Asia-Pacific Conference on Condensed Matter Physics 2022, Nov. 2022, English
    Oral presentation

  • 半金属半導体転移近傍にあるBi$_{1-x}$Sb$_x$における磁気抵抗異常
    山口侑真, 木下雄斗, 山田, 暉馨, 三宅厚志, 伏屋雄紀, 徳永将史
    日本物理学会秋季大会, 東京工業大学（大岡山キャンパス）, Sep. 2022, Japanese
    Oral presentation

  • Orbital origin of negative magnetoresistance and planar Hall effect in Weyl electron systems
    Akiyoshi Yamada, Yuki Fuseya
    International Conference on Low Temperature Physics, LT29, Aug. 2022, English
    Poster presentation

  • ワイル半金属における軌道由来の負の磁気抵抗とプレーナーホール効果
    山田 暉馨, 伏屋 雄紀
    SCTM2021 ワークショップ「超伝導物質、トポロジカル物質」 物質・材料研究機構, Nov. 2021, Japanese
    Oral presentation

  • Orbital origin of negative magnetoresistance and planar Hall effect in Weyl electron systems
    Akiyoshi Yamada, Yuki Fuseya
    The International Conference on Strongly Correlated Electron Systems 2021, Sep. 2021, English
    Oral presentation

  • ワイル電子系における軌道由来の負の磁気抵抗とプレーナーホール効果
    山田 暉馨, 伏屋 雄紀
    日本物理学会秋季大会，オンライン開催, Sep. 2021, Japanese
    Oral presentation

  • 量子極限下におけるBiのサイクロトロン共鳴 II
    竹端 寛治, 今中 康貴, underline{山田, 暉馨, 伏屋 雄紀, 木下 雄斗, 徳永 将史
    日本物理学会秋季大会，オンライン開催, Sep. 2021, Japanese
    Oral presentation

  • 半金属Biにおける強磁場下の非自明な磁気抵抗とプレーナーホール効果
    山田暉馨, 伏屋 雄紀
    第5回固体化学フォーラム研究会，オンライン, Jun. 2021, Japanese
    Poster presentation

  • Angular dependence of magnetoresistance and planar Hall effect in semimetals in strong magnetic fields
    Akiyoshi Yamada, Yuki Fuseya
    Asia-Pacific Conference on Research in High Magnetic Fields 2020, Dec. 2020, English
    Oral presentation

  • ランダウ量子化した半金属キャリアの電流磁気効果
    Akiyoshi Yamada, Yuki Fuseya
    PASPS25, 大阪大学, Nov. 2020, Japanese
    Oral presentation

  • 量子極限下におけるBiのサイクロトロン共鳴
    竹端 寛治, 今中 康貴, 山田, 暉馨, 伏屋 雄紀, 木下 雄斗, 徳永 将史
    日本物理学会秋季大会，名古屋大学, Sep. 2020, Japanese
    Oral presentation

  • 精密決定されたランダウ準位に基づくBi磁気抵抗の異方性解析
    山田 暉馨, 伏屋 雄紀
    日本物理学会秋季大会，名古屋大学, Sep. 2020, Japanese
    Oral presentation

  • Investigation of the inverse spin Hall effect in CuxO electrodes by using electrical spin injection and detection
    Akiyoshi Yamada, Taisei Ariki, Kohei Ohnishi, Yuichiro Ando, Takashi Kimura, Masashi Shiraishi
    62nd Annual Conference on Magnetism and Magnetic Materials 2017, Nov. 2017, English
    Poster presentation

  • Inverse spin Hall effect in surface oxidized Cu layer in Cu based lateral spin valves
    Akiyoshi Yamada, Taisei Ariki, Kohei Ohnishi, Yuichiro Ando, Takashi Kimura, Masashi Shiraishi
    応用物理学会, Sep. 2017, Japanese
    Oral presentation

■ Affiliated Academic Society
  • 日本物理学会
    Dec. 2019 - Present

■ Research Themes
  • 強磁場極限における特異な電気伝導の理論的解明
    山田 暉馨
    日本学術振興会, 科学研究費助成事業, 研究活動スタート支援, 神戸大学, Jul. 2025 - Mar. 2027

  • Quantum-classical correspondence and non-equilibrium to equilibrium crossover in galvanomagnetic effects
    村田学術振興・教育財団, 研究者海外派遣援助, 神戸大学, Jul. 2025

  • Quantum–classical correspondence and dissipative to dissipationless crossover in magnetotransport phenomena
    湯川記念財団, 望月基金 国際会議派遣, 電気通信大学, Jul. 2024

■ Media Coverage
  • Exotic or classical? Improved tools can distinguish materials
    CSIRO Publishing, Jun. 2026
    Internet

  • How Kobe University Clarifies 120-Degree Patterns in Magnetic Response
    Quantum Zeitgeist, Jun. 2026
    Internet

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