助教

岡村 嘉大　Yoshihiro Okamura

Biography

Original papers

1. "Gapped nodal planes drive a large topological Nernst effect in a chiral lattice antiferromagnet"
   N. D. Khanh, S. Minami, M. Hirschmann, T. Nomoto, M. C. Jiang, R. Yamada, D. Yamaguchi, Y. Hayashi, Y. Okamura, H. Watanabe, G. Y. Guo, Y. Takahashi, S. Seki, Y. Taguchi, Y. Tokura, R. Arita, and M. Hirschberger
   arXiv:2403.01113
2. "Large nonlinear optical magnetoelectric response in a noncentrosymmetric magnetic Weyl semimetal"
   K. Shoriki*, K. Moriishi*, Y. Okamura*, K. Yokoi, H. Usui, H. Murakawa, H. Sakai, N. Hanasaki, Y. Tokura, and Y. Takahashi (*equal contribution)
   Proceedings of the National Academy of Sciences of the United States of America 121, e2316910121 (2024).
3. "Terahertz field driven giant nonlinear phonon response in ferroelectric semicondutor In-doped (Sn,Pb)Te"
   H. Handa, Y. Okamura, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, Y. Tokura, and Y. Takahashi
   Phys. Rev. B 109, L081102 (2024).
4. "Observation of anomalous Hall resonance of massive Dirac fermions in topological kagome-lattice magnet"
   Y. Okamura, K. Shoriki, Y. Nomura, Y. Fujishiro, A. Kitaori, N. Kanazawa, R. Arita, Y. Tokura, and Y. Takahashi
   npj Quantum Materials 8, 57 (2023).
5. "Topological magneto-optical effect from skyrmion lattice"
   Y. D. Kato, Y. Okamura, M. Hirschberger, Y. Tokura, and Y. Takahashi
   Nature Communications 14, 5416 (2023).
6. "Band structures in orientation-controlled CuI thin films under epitaxial strain"
   M. Nakamura, S. Inagaki, Y. Okamura, M. Ogino, Y. Takahashi, K. Adachi, D. Hashizume, Y. Tokura, and M. Kawasaki
   Physical Review B 106, 125307 (2022).
7. "Terahertz lattice and charge dynamics in ferroelectric semiconductor SnxPb1-xTe"
   Y. Okamura, H. Handa, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, M. Kawasaki, Y. Tokura, and Y. Takahashi
   npj Quantum Materials 7, 91 (2022).
8. "Optical anomalous Hall effect enhanced by flat bands in ferromagnetic van der Waals semimetal"
   Y. D. Kato, Y. Okamura, S. Minami, R. Fujimura, M. Mogi, R. Yoshimi, A. Tsukazaki, K. Takahashi, M. Kawasaki, R. Arita, Y. Tokura, and Y. Takahashi
   npj Quantum Materials 7, 73 (2022).
9. "Photovoltaic effect by soft phonon excitation"
   Y. Okamura, T. Morimoto, N. Ogawa, Y. Kaneko, G-Y. Guo, M. Kawasaki, N. Naogaosa, Y. Tokura, and Y. Takahashi
   Proceedings of the National Academy of Sciences of the United States of America 119, e2122313119 (2022).
10. "Experimental signature of parity anomaly in semi-magnetic topological insulator"
    M. Mogi, Y. Okamura, M. Kawamura, R. Yoshimi, K. Yasuda, A. Tsukazaki, K. S. Takahashi, T. Morimoto, N. Nagaosa, M. Kawasaki, Y. Takahashi, and Y. Tokura
    Nature Physics 18, 390 (2022).
11. "Magneto-optical spectroscopy on Weyl nodes for anomalous and topological Hall effects in chiral MnGe"
    Y. Hayashi, Y. Okamura, N. Kanazawa, T. Yu, T. Koretsune, R. Arita, A. Tsukazaki, M. Ichikawa, M Kawasaki, Y. Tokura and Y. Takahashi
    Nature Communications 12, 5974 (2021).
12. "Heteroepitaxial growth of wide bandgap cuprous iodide films exhibiting clear free-exciton emission"
    S. Inagaki, M. Nakamura, Y. Okamura, M. Ogino, Y. Takahashi, L. C. Peng, X. Z. Yu, Y. Tokura, and M. Kawasaki,
    Applied Physics Letters 118, 012103 (2021).
13. "Giant magneto-optical responses in magnetic Weyl semimetal Co3Sn2S2"
    Y. Okamura, S. Minami, Y. Kato, Y. Fujishiro, Y. Kaneko, J. Ikeda, J. Muramoto, R. Kaneko, K. Ueda, V. Kocsis, Y. Taguchi, T. Koretsune, K. Fujiwara, A. Tsukazaki, R. Arita, Y. Tokura and Y. Takahashi,
    Nature Communications 11, 4619 (2020).
14. "Propagation dynamics of spin excitations along skyrmion strings"
    S. Seki, M. Garst, J. Waizner, R. Takagi, Y. Okamura, K. Kondou, F. Kagawa, Y. Otani, and Y. Tokura,
    Nature Communications 11, 256 (2020).
15. "Element-specific soft x-ray spectroscopy, scattering and imaging studies of the skyrmion-hosting compound Co8Zn8Mn4"
    V. Ukleev, Y. Yamasaki, D. Morikawa, K. Karube, K. Shibata, Y. Tokunaga, Y. Okamura, K. Amemiya, M. Valvidares, H. Nakao, Y. Taguchi, Y. Tokura, and T. Arima,
    Physical Review B 99, 144408 (2019).
16. "Microwave directional dichroism resonant with spin excitations in the polar ferromagnet GaV4S8"
    Y. Okamura, S. Seki, S. Bordacs, A. Butykai, V. Tsurkan, I. Kezsmarki, and Y. Tokura
    Phys. Rev. Lett. 122, 057202 (2019).
17. "Coherent resonant soft X-ray scattering study of magnetic textures in FeGe"
    V. Ukleev, Y. Yamasaki, D. Morikawa, N. Kanazawa, Y. Okamura, H. Nakao, Y. Tokura, T. Arima
    Quantum Beam Science 2, 3 (2018).
18. "Stabilization of magnetic skyrmions by uniaxial tensile strain"
    S. Seki, Y. Okamura, K. Shibata, R. Takagi, N. D. Khahn, F. Kagawa, T. Arima, and Y. Tokura
    Phys. Rev. B 96, 220404 (2017).
19. "Emergence and magnetic-field variation of chiral-soliton lattice and skyrmion lattice in the strained helimagnet Cu2OSeO3"
    Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, and Y. Tokura
    Phys. Rev. B 96, 174417 (2017).
20. "Current-induced viscoelastic topological unwinding of metastable skyrmion strings"
    F. Kagawa, H. Oike, W. Koshibae, A. Kikkawa, Y. Okamura, Y. Taguchi, N. Nagaosa, and Y. Tokura
    Nat. Commun. 8, 1332 (2017).
21. "Directional electric-field induced transformation from skyrmion lattice to distinct helices in multiferroic Cu2OSeO3"
    Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, and Y. Tokura
    Phys. Rev. B 95, 184411 (2017).
22. "Transition to and from the skyrmion lattice phase by electric fields in a magnetoelectric compound"
    Y. Okamura, F. Kagawa, S. Seki, and Y. Tokura
    Nat. Commun. 7, 12669 (2016).
23. "Magnetochiral nonreciprocity of volume spin wave propagation in chiral-lattice ferromagnets"
    S. Seki, Y. Okamura, K. Kondou, K. Shibata, M. Kubota, R. Takagi, F. Kagawa, M. Kawasaki, G. Tatara, Y. Otani, and Y. Tokura
    Phys. Rev. B 93, 235131 (2016).
24. "Microwave magnetochiral dichroism in the chiral-lattice magnet Cu2OSeO3"
    Y. Okamura, F. Kagawa, M. Mochizuki, M. Kubota, S. Seki, S. Ishiwata, M. Kawasaki, Y. Onose, and Y. Tokura
    Phys. Rev. Lett. 114, 197202 (2015).
25. "Microwave magnetoelectric effect via skyrmion resonance in a helimagnetic multiferroic"
    Y. Okamura, F. Kagawa, M. Mochizuki, M. Kubota, S. Seki, S. Ishiwata, M. Kawasaki, Y. Onose, and Y. Tokura
    Nat. Commun. 4, 2391 (2013).
26. "Observation of Magnetic excitation of Skyrmion Crystal in a Helimagnec Insulator Cu2OSeO3"
    Y. Onose, Y. Okamura, S. Seki, S. Ishiwata, and Y. Tokura
    Phys. Rev. Lett. 109, 037603 (2012).

国際会議発表

1. "Large terahertz resonance in MnGe thin film" (APS March Meeting, Boston, America, March 2019) Y. Okamura, Y. Hayashi, N. Kanazawa, A. Tsukazaki, M. Kawasaki, M. Ichikawa, Y. Tokura, Y. Takahashi
2. "Microwave magnetochiral dichroism in chiral-lattice magnet Cu2OSeO3"
   (Workshop on "Topological Magnets" Wako Saitama Japan, May 2015)
   Y. Okamura, F. Kagawa, S. Seki,M. Kubota, M. Kawasaki, and Y. Tokura
3. "Microwave magnetochiral dichroism resonant with electromagnons in a chiral-lattice magnet Cu2OSeO3"
   (APS March Meeting San Antonio America, March 2015)
   Y. Okamura, F. Kagawa, S. Seki,M. Kubota, M. Kawasaki, and Y. Tokura
4. "Microwave magnetoelectric effect via skyrmion resonance in a helimagnetic multiferroic"
   (The 12th Asia Pacific Physics Conference A-1 Makuhari Chiba Japan, July 2013)
   Y. Okamura, F. Kagawa, M. Mochizuki, M. Kubota, S. Seki, S. Ishiwata, M. Kawasaki, Y. Onose and Y. Tokura

特許

受賞

研究助成

1. 基盤研究B（2024-2026年度）
   
2. 挑戦的研究（萌芽）（2022-2023年度）
   
3. 新学術領域研究（研究領域提案型）「量子液晶の物性科学」（2022-2023年度）
   
4. 若手研究（2019-2020年度）
   
5. スタートアップ（2017-2018年度）
   
6. 日本学術振興会特別研究員
   

財団助成

1. 旭硝子財団（2023年度）
   
2. 池谷財団（2023年度）
   
3. 村田財団（2022年度）
   
4. みずほ学術振興会財団（2020-2021年度）
   
5. 村田財団（2018-2019年度）