Details of the Researcher

PHOTO

Shoya Sakamoto
Section
Institute for Materials Research
Job title
Associate Professor
Degree

  • 博士（理学）（東京大学）

  • 修士（理学）（東京大学）

e-Rad No.
50868114
Researcher ID
AAB-5611-2020

Research History 4

  • 2025/03 - Present
    Tohoku University　Institute for Materials Research　Associate professor

  • 2019/10 - 2025/02
    The University of Tokyo　The Institute for Solid State Physics　Assistant Professor

  • 2018/04 - 2019/09
    Stanford University　SLAC, SIMES　JSPS Overseas Research Fellowship

  • 2017/04 - 2018/03
    The University of Tokyo　Department of Physics　JSPS research fellowship for young Scientist (DC2)

Education 2

  • The University of Tokyo　School of Science　Department of Physics

    2013/04 - 2018/03

  • The University of Tokyo　School of Science　Department of Physics

    2009/04 - 2013/03

Committee Memberships 1

  • PF News編集委員

    2022/04 - 2024/03

Professional Memberships 3

  • 応用物理学会

    2014/06 - Present

  • 日本物理学会

    2013/06 - Present

  • 日本放射光学会

    2015/10 -

Research Areas 1

  • Natural sciences / Magnetism, superconductivity, and strongly correlated systems /

Awards 5

  1. 第28回 日本放射光学会奨励賞

    2024/01

  2. 東京大学理学系研究科 研究奨励賞

    2018/03

  3. 応用物理学会 英語講演奨励賞

    2016/09

  4. PASPS9 Young Researcher Best Poster Award

    2016/08

  5. 学生発表賞

    2016/01　放射光学会

Papers 59

  1. Interfacial alloying as a source of stacking order dependence of the Gilbert damping constant of the Fe/Pt bilayer system

    Erkang Wei, Shoya Sakamoto, Jieyi Chen, Hidetoshi Kosaki, Tempei Hatajiri, Shinji Miwa

    Physical Review B　2025/07/25

    DOI： 10.1103/7s36-k2n3 　

  2. Observation of chiral domain walls in an octupole-ordered antiferromagnet

    Moeta Tsukamoto, Zhewen Xu, Tomoya Higo, Kouta Kondou, Kento Sasaki, Mihiro Asakura, Shoya Sakamoto, Pietro Gambardella, Shinji Miwa, YoshiChika Otani, Satoru Nakatsuji, Christian L. Degen, Kensuke Kobayashi

    Physical Review B　2025/07/17

    DOI： 10.1103/njnm-nl6n 　

  3. Antiferromagnetic spin-torque diode effect in a kagome Weyl semimetal

    Shoya Sakamoto, Takuya Nomoto, Tomoya Higo, Yuki Hibino, Tatsuya Yamamoto, Shingo Tamaru, Yoshinori Kotani, Hidetoshi Kosaki, Masanobu Shiga, Daisuke Nishio-Hamane, Tetsuya Nakamura, Takayuki Nozaki, Kay Yakushiji, Ryotaro Arita, Satoru Nakatsuji, Shinji Miwa

    Nature Nanotechnology　2025/02

    DOI： 10.1038/s41565-024-01820-0 　

  4. Anisotropy of the Gilbert damping constant in NiFe grown on the chiral antiferromagnet Mn3Sn

    Hidetoshi Kosaki, Shoya Sakamoto, Tempei Hatajiri, Tomoya Higo, Satoru Nakatsuji, Shinji Miwa

    Physical Review B　2025/01/22

    DOI： 10.1103/PhysRevB.111.024418 　

  5. Relationship between orbital moment anisotropy, magnetocrystalline anisotropy, and Dzyaloshinskii-Moriya interaction in W/Co/Pt trilayers

    Zhendong Chi, Yong-Chang Lau, Vanessa Li Zhang, Goro Shibata, Shoya Sakamoto, Yosuke Nonaka, Keisuke Ikeda, Yuxuan Wan, Masahiro Suzuki, Masashi Kawaguchi, Masako Suzuki-Sakamaki, Kenta Amemiya, Naomi Kawamura, Masaichiro Mizumaki, Motohiro Suzuki, Hyunsoo Yang, Masamitsu Hayashi, Atsushi Fujimori

    Physical Review B　2024/11/07

    DOI： 10.1103/PhysRevB.110.184401 　

  6. Bulk and surface uniformity of magnetic and electronic structures in epitaxial W/Mn3Sn/MgO films revealed by fluorescence- and electron-yield x-ray magnetic circular dichroism

    Shoya Sakamoto, Tomoya Higo, Yoshinori Kotani, Hidetoshi Kosaki, Tetsuya Nakamura, Satoru Nakatsuji, Shinji Miwa

    Physical Review B　110　(6)　2024/08/29

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevB.110.L060412 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  7. Gilbert damping of NiFe thin films grown on two-dimensional chiral hybrid lead-iodide perovskites

    Tempei Hatajiri, Shoya Sakamoto, Hidetoshi Kosaki, Zikang Tian, Miuko Tanaka, Toshiya Ideue, Keiichi Inoue, Daigo Miyajima, Shinji Miwa

    Physical Review B　110　(5)　2024/08/23

    Publisher: American Physical Society (APS)

    DOI： 10.1103/physrevb.110.054435 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  8. Influence of alkali-fluoride insertion layers on the perpendicular magnetic anisotropy at the Fe/MgO interface

    Jieyi Chen, Shoya Sakamoto, Shinji Miwa

    Physical Review B　2024/02/15

    DOI： 10.1103/PhysRevB.109.064413 　

  9. Development of deflector mode for spin-resolved time-of-flight photoemission spectroscopy

    Xue Han, Jason Qu, Shoya Sakamoto, Dongyu Liu, Dandan Guan, Jin Liu, Hui Li, Costel R. Rotundu, Nord Andresen, Chris Jozwiak, Zahid Hussain, Zhi-Xun Shen, Jonathan A. Sobota

    Review of Scientific Instruments　2023/10/01

    DOI： 10.1063/5.0168447 　

  10. Ferromagnetism induced by hybridization of Fe 3d orbitals with ligand InSb bands in the n -type ferromagnetic semiconductor (In,Fe)Sb

    Ryo Okano, Tomoki Hotta, Takahito Takeda, Kohsei Araki, Kengo Takase, Le Duc Anh, Shoya Sakamoto, Yukiharu Takeda, Atsushi Fujimori, Masaaki Tanaka, Masaki Kobayashi

    Physical Review B　107　(20)　2023/05/25

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevB.107.205205 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  11. Origin of magnetically dead layers in spinel ferrites MFe2O4 grown on Al2O3 : Effects of postdeposition annealing studied by XMCD

    Yosuke Nonaka, Yuki K. Wakabayashi, Goro Shibata, Shoya Sakamoto, Keisuke Ikeda, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Arata Tanaka, Masaaki Tanaka, Atsushi Fujimori

    Physical Review Materials　2023/04/27

    DOI： 10.1103/PhysRevMaterials.7.044413 　

  12. Observation of large spin conversion anisotropy in bismuth Peer-reviewed

    Naoki Fukumoto, Ryo Ohshima, Motomi Aoki, Yuki Fuseya, Masayuki Matsushima, Ei Shigematsu, Teruya Shinjo, Yuichiro Ando, Shoya Sakamoto, Masanobu Shiga, Shinji Miwa, Masashi Shiraishi

    Proceedings of the National Academy of Sciences　120　(13)　2023/03/28

    Publisher: Proceedings of the National Academy of Sciences

    DOI： 10.1073/pnas.2215030120 　

    ISSN： 0027-8424

    eISSN： 1091-6490

    More details Close

    While the effective g -factor can be anisotropic due to the spin-orbit interaction (SOI), its existence in solids cannot be simply asserted from a band structure, which hinders progress on studies from such viewpoints. The effective g -factor in bismuth (Bi) is largely anisotropic; especially for holes at T -point, the effective g -factor perpendicular to the trigonal axis is negligibly small (<0.112), whereas the effective g -factor along the trigonal axis is very large (62.7). We clarified in this work that the large anisotropy of effective g -factor gives rise to the large spin conversion anisotropy in Bi from experimental and theoretical approaches. Spin-torque ferromagnetic resonance was applied to estimate the spin conversion efficiency in rhombohedral (110) Bi to be 17 to 27%, which is unlike the negligibly small efficiency in Bi(111). Harmonic Hall measurements support the large spin conversion efficiency in Bi(110). A large spin conversion anisotropy as the clear manifestation of the anisotropy of the effective g -factor is observed. Beyond the emblematic case of Bi, our study unveiled the significance of the effective g -factor anisotropy in condensed-matter physics and can pave a pathway toward establishing novel spin physics under g -factor control.

  13. Magnetic anisotropy of Fe/MgO interfaces inserted with alkali halide layers

    Jieyi Chen, Shoya Sakamoto, Hidetoshi Kosaki, Shinji Miwa

    Physical Review B　107　(9)　2023/03/17

    Publisher: American Physical Society (APS)

    DOI： 10.1103/physrevb.107.094420 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  14. Reversal of spin-polarization near the Fermi level of the Rashba semiconductor BiTeCl

    J. Qu, X. Han, S. Sakamoto, C. J. Jia, J. Liu, H. Li, D. Guan, Y.-J. Zeng, M. Schüler, P. S. Kirchmann, B. Moritz, Z. Hussain, T. P. Devereaux, Z.-X. Shen, J. A. Sobota

    npj Quantum Materials　2023/03/02

    DOI： 10.1038/s41535-023-00546-x 　

  15. Octupole-driven magnetoresistance in an antiferromagnetic tunnel junction

    Xianzhe Chen, Tomoya Higo, Katsuhiro Tanaka, Takuya Nomoto, Hanshen Tsai, Hiroshi Idzuchi, Masanobu Shiga, Shoya Sakamoto, Ryoya Ando, Hidetoshi Kosaki, Takumi Matsuo, Daisuke Nishio-Hamane, Ryotaro Arita, Shinji Miwa, Satoru Nakatsuji

    Nature　613　(7944)　490-495　2023/01/19

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41586-022-05463-w 　

    ISSN： 0028-0836

    eISSN： 1476-4687

    More details Close

    Abstract The tunnelling electric current passing through a magnetic tunnel junction (MTJ) is strongly dependent on the relative orientation of magnetizations in ferromagnetic electrodes sandwiching an insulating barrier, rendering efficient readout of spintronics devices1–5. Thus, tunnelling magnetoresistance (TMR) is considered to be proportional to spin polarization at the interface1 and, to date, has been studied primarily in ferromagnets. Here we report observation of TMR in an all-antiferromagnetic tunnel junction consisting of Mn3Sn/MgO/Mn3Sn (ref. 6). We measured a TMR ratio of around 2% at room temperature, which arises between the parallel and antiparallel configurations of the cluster magnetic octupoles in the chiral antiferromagnetic state. Moreover, we carried out measurements using a Fe/MgO/Mn3Sn MTJ and show that the sign and direction of anisotropic longitudinal spin-polarized current in the antiferromagnet7 can be controlled by octupole direction. Strikingly, the TMR ratio (about 2%) of the all-antiferromagnetic MTJ is much larger than that estimated using the observed spin polarization. Theoretically, we found that the chiral antiferromagnetic MTJ may produce a substantially large TMR ratio as a result of the time-reversal, symmetry-breaking polarization characteristic of cluster magnetic octupoles. Our work lays the foundation for the development of ultrafast and efficient spintronic devices using antiferromagnets8–10.

  16. Origin of enhanced interfacial perpendicular magnetic anisotropy in LiF-inserted Fe/MgO interface

    Shoya Sakamoto, Takayuki Nozaki, Shinji Yuasa, Kenta Amemiya, Shinji Miwa

    Physical Review B　2022/11/14

    DOI： 10.1103/PhysRevB.106.174410 　

  17. Cr doping-induced ferromagnetism in the spin-glass Cd1−xMnxTe studied by x-ray magnetic circular dichroism

    V.K. Verma, S. Sakamoto, K. Ishikawa, V.R. Singh, K. Ishigami, G. Shibata, T. Kadono, T. Koide, S. Kuroda, A. Fujimori

    Physica B: Condensed Matter　642　414129-414129　2022/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.physb.2022.414129 　

    ISSN： 0921-4526

  18. Perpendicular full switching of chiral antiferromagnetic order by current

    Tomoya Higo, Kouta Kondou, Takuya Nomoto, Masanobu Shiga, Shoya Sakamoto, Xianzhe Chen, Daisuke Nishio-Hamane, Ryotaro Arita, Yoshichika Otani, Shinji Miwa, Satoru Nakatsuji

    Nature　607　(7919)　474-479　2022/07/21

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41586-022-04864-1 　

    ISSN： 0028-0836

    eISSN： 1476-4687

  19. Magnetic Properties and Electronic Configurations of Mn Ions in the Diluted Magnetic Semiconductor Ba1−xKx(Zn1−yMny)2As2 Studied by X-ray Magnetic Circular Dichroism and Resonant Inelastic X-ray Scattering

    Hakuto Suzuki, Guoqiang Zhao, Jun Okamoto, Shoya Sakamoto, Zhi-Yin Chen, Yosuke Nonaka, Goro Shibata, Kan Zhao, Bijuan Chen, Wen-Bin Wu, Fan-Hsiu Chang, Hong-Ji Lin, Chien-Te Chen, Arata Tanaka, Masaki Kobayashi, Bo Gu, Sadamichi Maekawa, Yasutomo J. Uemura, Changqing Jin, Di-Jing Huang, Atsushi Fujimori

    Journal of the Physical Society of Japan　91　(6)　2022/06/15

    Publisher: Physical Society of Japan

    DOI： 10.7566/jpsj.91.064710 　

    ISSN： 0031-9015

    eISSN： 1347-4073

  20. Development of magnetism in Fe-doped magnetic semiconductors: Resonant photoemission and x-ray magnetic circular dichroism studies of (Ga,Fe)As

    Takahito Takeda, Shoya Sakamoto, Le Duc Anh, Yukiharu Takeda, Shin-ichi Fujimori, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Atsushi Fujimori, Masaaki Tanaka, Masaki Kobayashi

    Physical Review B　105　(19)　2022/05/31

    DOI： 10.1103/PhysRevB.105.195155 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  21. Control of perpendicular magnetic anisotropy at the Fe/MgO interface by phthalocyanine insertion

    Shoya Sakamoto, Edward Jackson, Takeshi Kawabe, Takuya Tsukahara, Yoshinori Kotani, Kentaro Toyoki, Emi Minamitani, Yoshio Miura, Tetsuya Nakamura, Atsufumi Hirohata, Shinji Miwa

    Physical Review B　105　(18)　2022/05/13

    Publisher: American Physical Society (APS)

    DOI： 10.1103/physrevb.105.184414 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  22. Connection between coherent phonons and electron-phonon coupling in Sb (111)

    S. Sakamoto, N. Gauthier, P. S. Kirchmann, J. A. Sobota, Z.-X. Shen

    Physical Review B　2022/04/27

    DOI： 10.1103/PhysRevB.105.L161107 　

  23. Chirality-Induced Magnetoresistance Due to Thermally Driven Spin Polarization

    Kouta Kondou, Masanobu Shiga, Shoya Sakamoto, Hiroyuki Inuzuka, Atsuko Nihonyanagi, Fumito Araoka, Masaki Kobayashi, Shinji Miwa, Daigo Miyajima, YoshiChika Otani

    Journal of the American Chemical Society　144　(16)　7302-7307　2022/04/27

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/jacs.2c00496 　

    ISSN： 0002-7863

    eISSN： 1520-5126

  24. Electron Correlation Enhances Orbital Polarization at a Ferromagnetic Metal/Insulator Interface: Depth-Resolved X-ray Magnetic Circular Dichroism and First-Principles Study

    Shoya Sakamoto, Masahito Tsujikawa, Masafumi Shirai, Kenta Amemiya, Shinji Miwa

    ACS Applied Electronic Materials　4　(4)　1794-1799　2022/04/26

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/acsaelm.2c00049 　

    eISSN： 2637-6113

  25. Magnetic anisotropy of the van der Waals ferromagnet Cr2Ge2Te6 studied by angular-dependent x-ray magnetic circular dichroism

    M. Suzuki, B. Gao, G. Shibata, S. Sakamoto, Y. Nonaka, K. Ikeda, Z. Chi, Y.-X. Wan, T. Takeda, Y. Takeda, T. Koide, A. Tanaka, M. Kobayashi, S.-W. Cheong, A. Fujimori

    Physical Review Research　4　(1)　2022/02/18

    Publisher: American Physical Society ({APS})

    DOI： 10.1103/PhysRevResearch.4.013139 　

  26. Observation of spontaneous x-ray magnetic circular dichroism in a chiral antiferromagnet

    Shoya Sakamoto, Tomoya Higo, Masanobu Shiga, Kenta Amemiya, Satoru Nakatsuji, Shinji Miwa

    Physical Review B　104　(13)　2021/10/27

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevB.104.134431 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  27. Influence of epitaxial strain on the perpendicular magnetic anisotropy of Fe/MgO systems

    Masanobu Shiga, Shoya Sakamoto, Takaya Tsujikawa, Ryoya Ando, Kenta Amemiya, Shinji Miwa

    Physical Review B　104　(14)　2021/10/14

    Publisher: American Physical Society ({APS})

    DOI： 10.1103/PhysRevB.104.L140406 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  28. Reduced magnetocrystalline anisotropy of CoFe2O4 thin films studied by angle-dependent x-ray magnetic circular dichroism

    Yosuke Nonaka, Yuki K. Wakabayashi, Goro Shibata, Shoya Sakamoto, Keisuke Ikeda, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Tsuneharu Koide, Masaaki Tanaka, Ryosho Nakane, Atsushi Fujimori

    AIP Advances　2021/08/01

    DOI： 10.1063/5.0057576 　

  29. Large Hall Signal due to Electrical Switching of an Antiferromagnetic Weyl Semimetal State

    Hanshen Tsai, Tomoya Higo, Kouta Kondou, Shoya Sakamoto, Ayuko Kobayashi, Takumi Matsuo, Shinji Miwa, Yoshichika Otani, Satoru Nakatsuji

    Small Science　1　(5)　2000025-2000025　2021/05/15

    Publisher: Wiley

    DOI： 10.1002/smsc.202000025 　

    ISSN： 2688-4046

    eISSN： 2688-4046

  30. Giant Effective Damping of Octupole Oscillation in an Antiferromagnetic Weyl Semimetal

    Shinji Miwa, Satoshi Iihama, Takuya Nomoto, Takahiro Tomita, Tomoya Higo, Muhammad Ikhlas, Shoya Sakamoto, YoshiChika Otani, Shigemi Mizukami, Ryotaro Arita, Satoru Nakatsuji

    Small Science　1　(5)　2000062-2000062　2021/05

    Publisher: Wiley

    DOI： 10.1002/smsc.202000062 　

    ISSN： 2688-4046

    eISSN： 2688-4046

  31. Low Gilbert damping in epitaxial thin films of the nodal-line semimetal D03−Fe3Ga

    Shoya Sakamoto, Tomoya Higo, Shingo Tamaru, Hitoshi Kubota, Kay Yakushiji, Satoru Nakatsuji, Shinji Miwa

    Physical Review B　103　(16)　2021/04/20

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevB.103.165122 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  32. Anisotropic Spin Distribution and Perpendicular Magnetic Anisotropy in a Layered Ferromagnetic Semiconductor (Ba,K)(Zn,Mn)2As2

    Shoya Sakamoto, Guoqiang Zhao, Goro Shibata, Zheng Deng, Kan Zhao, Xiancheng Wang, Yosuke Nonaka, Keisuke Ikeda, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Tsuneharu Koide, Arata Tanaka, Sadamichi Maekawa, Yasutomo J. Uemura, Changqing Jin, Atsushi Fujimori

    ACS Applied Electronic Materials　3　(2)　789-794　2021/02/23

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/acsaelm.0c00938 　

    ISSN： 2637-6113

    eISSN： 2637-6113

  33. Evolution of Fe 3d impurity band state as the origin of high Curie temperature in the p -type ferromagnetic semiconductor (Ga,Fe)Sb

    Takahito Takeda, Shoya Sakamoto, Kohsei Araki, Yuita Fujisawa, Le Duc Anh, Nguyen Thanh Tu, Yukiharu Takeda, Shin-ichi Fujimori, Atsushi Fujimori, Masaaki Tanaka, Masaki Kobayashi

    Physical Review B　102　(24)　2020/12/23

    DOI： 10.1103/PhysRevB.102.245203 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  34. Chirality-induced effective magnetic field in a phthalocyanine molecule

    Shinji Miwa, Kouta Kondou, Shoya Sakamoto, Atsuko Nihonyanagi, Fumito Araoka, YoshiChika Otani, Daigo Miyajima

    Applied Physics Express　13　(11)　2020/11/01

    DOI： 10.35848/1882-0786/abbf67 　

    ISSN： 1882-0778

    eISSN： 1882-0786

  35. Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film

    Shoya Sakamoto, Kenichi Kaminaga, Daichi Oka, Ryu Yukawa, Masafumi Horio, Yuichi Yokoyama, Kohei Yamamoto, Kou Takubo, Yosuke Nonaka, Keisuke Koshiishi, Masaki Kobayashi, Arata Tanaka, Akira Yasui, Eiji Ikenaga, Hiroki Wadati, Hiroshi Kumigashira, Tomoteru Fukumura, Atsushi Fujimori

    PHYSICAL REVIEW MATERIALS　4　(9)　2020/09

    DOI： 10.1103/PhysRevMaterials.4.095001 　

    ISSN： 2475-9953

  36. Sizable spin-transfer torque in the Bi/Ni80Fe20 bilayer film

    Masayuki Matsushima, Shinji Miwa, Shoya Sakamoto, Teruya Shinjo, Ryo Ohshima, Yuichiro Ando, Yuki Fuseya, Masashi Shiraishi

    APPLIED PHYSICS LETTERS　117　(4)　2020/07

    DOI： 10.1063/5.0009798 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  37. Voltage-controlled magnetic anisotropy in an ultrathin nickel film studied by operando x-ray magnetic circular dichroism spectroscopy

    Risa Miyakaze, Shoya Sakamoto, Takeshi Kawabe, Takuya Tsukahara, Yoshinori Kotani, Kentaro Toyoki, Tetsuya Nakamura, Minori Goto, Yoshishige Suzuki, Shinji Miwa

    PHYSICAL REVIEW B　102　(1)　2020/07

    DOI： 10.1103/PhysRevB.102.014419 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  38. Magnetization process of the insulating ferromagnetic semiconductor (Al,Fe)Sb

    Shoya Sakamoto, Yosuke Nonaka, Keisuke Ikeda, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Atsushi Fujimori, Le Duc Anh, Pham Nam Hai, Yukiharu Takeda, Yuji Saitoh, Masaki Kobayashi, Masaaki Tanaka, Yuki K. Wakabayashi, Hiroshi Yamagami

    PHYSICAL REVIEW B　101　(7)　2020/02

    DOI： 10.1103/PhysRevB.101.075204 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  39. Nature of Carrier Doping in T'-La(1.8-x)Eu(0.2)SrxCuO(4) Studied by X-Ray Photoemission and Absorption Spectroscopy Peer-reviewed

    Chun Lin, Masafumi Horio, Takayuki Kawamata, Shin Saito, Keisuke Koshiishi, Shoya Sakamoto, Yujun Zhang, Kohei Yamamoto, Keisuke Ikeda, Yasuyuki Hirata, Kou Takubo, Hiroki Wadati, Akira Yasui, Yasumasa Takagi, Eiji Ikenaga, Tadashi Adachi, Yoji Koike, Atsushi Fujimori

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN　88　(11)　115004-115004　2019/11

    DOI： 10.7566/JPSJ.88.115004 　

    ISSN： 0031-9015

  40. Chemical trend in the electronic structure of Fe-doped III-V semiconductors and possible origin of ferromagnetism: A first-principles study Peer-reviewed

    Shoya Sakamoto, Atsushi Fujimori

    JOURNAL OF APPLIED PHYSICS　126　(17)　173910-173910　2019/11

    DOI： 10.1063/1.5124704 　

    ISSN： 0021-8979

    eISSN： 1089-7550

  41. Electronic structure of the high-T-C ferromagnetic semiconductor (Ga,Fe)Sb: X-ray magnetic circular dichroism and resonance photoemission spectroscopy studies Peer-reviewed

    Shoya Sakamoto, Nguyen Thanh Tu, Yukiharu Takeda, Shin-ichi Fujimori, Pham Nam Hai, Le Duc Anh, Yuki K. Wakabayashi, Goro Shibata, Masafumi Horio, Keisuke Ikeda, Yuji Saitoh, Hiroshi Yamagami, Masaaki Tanaka, Atsushi Fujimori

    PHYSICAL REVIEW B　100　(3)　2019/07

    DOI： 10.1103/PhysRevB.100.035204 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  42. Anisotropic Charge Distribution Induced by Spin Polarization in La0.6Sr0.4MnO3 Thin Films Studied by X-ray Magnetic Linear Dichroism Peer-reviewed

    Goro Shibata, Kohei Yoshimatsu, Keisuke Ishigami, Takayuki Harano, Yukio Takahashi, Shoya Sakamoto, Yosuke Nonaka, Toshiharu Kadono, Mitsuho Furuse, Schuichiro Fuchino, Makoto Okano, Jun-ichi Fujihira, Akira Uchida, Kazunori Watanabe, Hideyuki Fujihira, Seiichi Fujihira, Arata Tanaka, Hiroshi Kumigashira, Tsuneharu Koide, Atsushi Fujimori

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN　87　(11)　2018/11

    DOI： 10.7566/JPSJ.87.114713 　

    ISSN： 0031-9015

  43. Cation distribution and magnetic properties in ultrathin (Ni1-xCox)Fe2O4 (x=0-1) layers on Si(111) studied by soft x-ray magnetic circular dichroism Peer-reviewed

    Yuki K. Wakabayashi, Yosuke Nonaka, Yukiharu Takeda, Shoya Sakamoto, Keisuke Ikeda, Zhendong Chi, Goro Shibata, Arata Tanaka, Yuji Saitoh, Hiroshi Yamagami, Masaaki Tanaka, Atsushi Fujimori, Ryosho Nakane

    PHYSICAL REVIEW MATERIALS　2　(10)　2018/10

    DOI： 10.1103/PhysRevMaterials.2.104416 　

    ISSN： 2475-9953

  44. Electronic Structure of Ce-Doped and -Undoped Nd2CuO4 Superconducting Thin Films Studied by Hard X-Ray Photoemission and Soft X-Ray Absorption Spectroscopy Peer-reviewed

    M. Horio, Y. Krockenberger, K. Yamamoto, Y. Yokoyama, K. Takubo, Y. Hirata, S. Sakamoto, K. Koshiishi, A. Yasui, E. Ikenaga, S. Shin, H. Yamamoto, H. Wadati, A. Fujimori

    Physical Review Letters　120　(25)　2018/06/21

    Publisher: American Physical Society

    DOI： 10.1103/PhysRevLett.120.257001 　

    ISSN： 1079-7114 0031-9007

    eISSN： 1079-7114

  45. Electronic states and possible origin of the orbital-glass state in a nearly metallic spinel cobalt vanadate: An x-ray magnetic circular dichroism study Peer-reviewed

    Yosuke Nonaka, Goro Shibata, Rui Koborinai, Keisuke Ishigami, Shoya Sakamoto, Keisuke Ikeda, Zhendong Chi, Tsuneharu Koide, Arata Tanaka, Takuro Katsufuji, Atsushi Fujimori

    PHYSICAL REVIEW B　97　(20)　2018/05

    DOI： 10.1103/PhysRevB.97.205126 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  46. Local magnetic states of the weakly ferromagnetic iron-based superconductor Sr<inf>2</inf>VFeAsO<inf>3−δ</inf> studied by X-ray magnetic circular dichroism Peer-reviewed

    Horio M, Takeda Y, Namiki H, Katagiri T, Wakabayashi Y.K, Sakamoto S, Nonaka Y, Shibata G, Ikeda K, Saitoh Y, Yamagami H, Sasagawa T, Fujimori A

    Journal of the Physical Society of Japan　87　(10)　2018

    DOI： 10.7566/JPSJ.87.105001 　

    ISSN： 0031-9015

    eISSN： 1347-4073

  47. Anisotropic spin-density distribution and magnetic anisotropy of strained La1-xSrxMnO3 thin films: angle-dependent x-ray magnetic circular dichroism Peer-reviewed

    Goro Shibata, Miho Kitamura, Makoto Minohara, Kohei Yoshimatsu, Toshiharu Kadono, Keisuke Ishigami, Takayuki Harano, Yukio Takahashi, Shoya Sakamoto, Yosuke Nonaka, Keisuke Ikeda, Zhendong Chi, Mitsuho Furuse, Shuichiro Fuchino, Makoto Okano, Jun-ichi Fujihira, Akira Uchida, Kazunori Watanabe, Hideyuki Fujihira, Seiichi Fujihira, Arata Tanaka, Hiroshi Kumigashira, Tsuneharu Koide, Atsushi Fujimori

    NPJ QUANTUM MATERIALS　3　(1)　2018/01

    DOI： 10.1038/s41535-018-0077-4 　

    eISSN： 2397-4648

  48. Magnetic anisotropy of L1(0)-ordered FePt thin films studied by Fe and Pt L-2;3-edges x-ray magnetic circular dichroism Peer-reviewed

    K. Ikeda, T. Seki, G. Shibata, T. Kadono, K. Ishigami, Y. Takahashi, M. Horio, S. Sakamoto, Y. Nonaka, M. Sakamaki, K. Amemiya, N. Kawamura, M. Suzuki, K. Takanashi, A. Fujimori

    APPLIED PHYSICS LETTERS　111　(14)　2017/10

    DOI： 10.1063/1.4993077 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  49. Effects of cobalt substitution in L1(0) -(Fe,Co)Pt thin films Peer-reviewed

    Shoya Sakamoto, Kumar Srinivasan, Rui Zhang, Oleg Krupin, Keisuke Ikeda, Goro Shibata, Yosuke Nonaka, Zhendong Chi, Masako Sakamaki, Kenta Amemiya, Atsushi Fujimori, Antony Ajan

    PHYSICAL REVIEW B　96　(14)　2017/10

    DOI： 10.1103/PhysRevB.96.144437 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  50. Electronic structure and magnetic properties of magnetically dead layers in epitaxial CoFe2O4/Al2O3/Si(111) films studied by x-ray magnetic circular dichroism Peer-reviewed

    Yuki K. Wakabayashi, Yosuke Nonaka, Yukiharu Takeda, Shoya Sakamoto, Keisuke Ikeda, Zhendong Chi, Goro Shibata, Arata Tanaka, Yuji Saitoh, Hiroshi Yamagami, Masaaki Tanaka, Atsushi Fujimori, Ryosho Nakane

    PHYSICAL REVIEW B　96　(10)　2017/09

    DOI： 10.1103/PhysRevB.96.104410 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  51. Origin of robust nanoscale ferromagnetism in Fe-doped Ge revealed by angle-resolved photoemission spectroscopy and first-principles calculation Peer-reviewed

    S. Sakamoto, Y. K. Wakabayashi, Y. Takeda, S. -I. Fujimori, H. Suzuki, Y. Ban, H. Yamagami, M. Tanaka, S. Ohya, A. Fujimori

    PHYSICAL REVIEW B　95　(7)　2017/02

    DOI： 10.1103/PhysRevB.95.075203 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  52. Origin of the large positive magnetoresistance of Ge1-xMnx granular thin films Peer-reviewed

    Yuki K. Wakabayashi, Ryota Akiyama, Yukiharu Takeda, Masafumi Horio, Goro Shibata, Shoya Sakamoto, Yoshisuke Ban, Yuji Saitoh, Hiroshi Yamagami, Atsushi Fujimori, Masaaki Tanaka, Shinobu Ohya

    PHYSICAL REVIEW B　95　(1)　2017/01

    DOI： 10.1103/PhysRevB.95.014417 　

    ISSN： 2469-9950

    eISSN： 2469-9969

  53. Volume-wise destruction of the antiferromagnetic Mott insulating state through quantum tuning Peer-reviewed

    Benjamin A. Frandsen, Lian Liu, Sky C. Cheung, Zurab Guguchia, Rustem Khasanov, Elvezio Morenzoni, Timothy J. S. Munsie, Alannah M. Hallas, Murray N. Wilson, Yipeng Cai, Graeme M. Luke, Bijuan Chen, Wenmin Li, Changqing Jin, Cui Ding, Shengli Guo, Fanlong Ning, Takashi U. Ito, Wataru Higemoto, Simon J. L. Billinge, Shoya Sakamoto, Atsushi Fujimori, Taito Murakami, Hiroshi Kageyama, Jose Antonio Alonso, Gabriel Kotliar, Masatoshi Imada, Yasutomo J. Uemura

    NATURE COMMUNICATIONS　7　2016/08

    DOI： 10.1038/ncomms12519 　

    ISSN： 2041-1723

  54. Room-temperature local ferromagnetism and its nanoscale expansion in the ferromagnetic semiconductor Ge1-xFex Peer-reviewed

    Yuki K. Wakabayashi, Shoya Sakamoto, Yuki-haru Takeda, Keisuke Ishigami, Yukio Takahashi, Yuji Saitoh, Hiroshi Yamagami, Atsushi Fujimori, Masaaki Tanaka, Shinobu Ohya

    SCIENTIFIC REPORTS　6　2016/03

    DOI： 10.1038/srep23295 　

    ISSN： 2045-2322

  55. Magnetization process of the n -type ferromagnetic semiconductor (In,Fe)As:Be studied by x-ray magnetic circular dichroism Peer-reviewed

    S. Sakamoto, L. D. Anh, P. N. Hai, G. Shibata, Y. Takeda, M. Kobayashi, Y. Takahashi, T. Koide, M. Tanaka, A. Fujimori

    Physical Review B　93　(3)　2016/01/19

    Publisher: American Physical Society

    DOI： 10.1103/PhysRevB.93.035203 　

    ISSN： 2469-9969 2469-9950

  56. Photoemission and x-ray absorption studies of the isostructural to Fe-based superconductors diluted magnetic semiconductor Ba1-xKx(Zn1-yMny)(2)As-2 Peer-reviewed

    H. Suzuki, K. Zhao, G. Shibata, Y. Takahashi, S. Sakamoto, K. Yoshimatsu, B. J. Chen, H. Kumigashira, F-H Chang, H-J Lin, D. J. Huang, C. T. Chen, Bo Gu, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    PHYSICAL REVIEW B　91　(14)　2015/04

    DOI： 10.1103/PhysRevB.91.140401 　

    ISSN： 1098-0121

    eISSN： 1550-235X

  57. Room temperature local ferromagnetism and nanoscale domain growth in the ferromagnetic semiconductor GeFe

    Yuki K. Wakabayashi, Shoya Sakamoto, Yukiharu Takeda, Keisuke Ishigami, Yukio Takahashi, Yuji Saitoh, Hiroshi Yamagami, Atsushi Fujimori, Masaaki Tanaka, Shinobu Ohya

    2015/01/31

    Publisher: arXiv

    DOI： 10.48550/ARXIV.1502.00118 　

    More details Close

    We investigate the local electronic structure and magnetic properties of the group IV based ferromagnetic semiconductor, GeFe, using soft X ray magnetic circular dichroism. Our results show that the doped Fe 3d electrons are strongly hybridized with the Ge 4p states, and have an unusually large orbital magnetic moment relative to the spin magnetic moment; i.e., morb/mspin = 0.3. We find that local ferromagnetic domains, which are formed through ferromagnetic exchange interactions in the high Fe content regions of the GeFe films, exist at room temperature, well above the Curie temperature. We demonstrate the first observation of the intriguing nanoscale domain growth process in which ferromagnetic domains expand as the temperature decreases, followed by a transition of the entire film into a ferromagnetic state at the Curie temperature.

  58. Spin and orbital magnetic moments of Fe in the n-type ferromagnetic semiconductor (In,Fe) As Peer-reviewed

    M. Kobayashi, L. D. Anh, P. N. Hai, Y. Takeda, S. Sakamoto, T. Kadono, T. Okane, Y. Saitoh, H. Yamagami, Y. Harada, M. Oshima, M. Tanaka, A. Fujimori

    APPLIED PHYSICS LETTERS　105　(3)　2014/07

    DOI： 10.1063/1.4890733 　

    ISSN： 0003-6951

    eISSN： 1077-3118

  59. Temperature evolution of magnetic phases near the thickness-dependent metal-insulator transition in La1−xSrxMnO3 thin films observed by XMCD Peer-reviewed

    G. Shibata, K. Yoshimatsu, E. Sakai, K. Ishigami, S. Sakamoto, Y. Nonaka, F. -H. Chang, H. -J. Lin, D. -J. Huang, C. -T. Chen, H. Kumigashira, A. Fujimori

    JPS Conference Proceedings

Show all ︎Show first 5

Misc. 25

  1. 軟X線磁気円二色性によるスピントロニクス薄膜の電子構造と磁性 Invited

    日本放射光学会誌　37　(2)　155-158　2024/03

  2. Weyl反強磁性体Mn3Snのスピンダイナミクス Invited Peer-reviewed

    三輪真嗣, 坂本祥哉, 飯浜賢志, 野本拓也

    まぐね　17　(5)　233-240　2022/10

  3. Fe をドープした 強磁性半導体の電⼦構造と磁性 Invited

    坂本祥哉

    日本放射光学会誌　32　(2)　116-117　2019/03

  4. Magnetically-induced anisotropic charge distribution in La1-xSrxMnO3 thin films revealed by x-ray magnetic linear dichroism

    Shibata Goro, Fuchino Schuichiro, Okano Makoto, Fujihira Jun-ichi, Uchida Akira, Watanabe Kazunori, Fujihira Hideyuki, Fujihira Seiichi, Tanaka Arata, Kumigashira Hiroshi, Koide Tsuneharu, Yoshimatsu Kohei, Fujimori Atsushi, Ishigami Keisuke, Harano Takayuki, Takahashi Yukio, Sakamoto Shoya, Nonaka Yosuke, Kadono Toshiharu, Furuse Mitsuho

    Meeting Abstracts of the Physical Society of Japan　73　(0)　1538-1538　2018

    Publisher: The Physical Society of Japan

    DOI： 10.11316/jpsgaiyo.73.1.0_1538 　

  5. Si基板上に作製したCoFe2O4/Al2O3多層膜界面における磁気的デッドレイヤーの起源とその修復

    野中洋亮, 若林勇希, 芝田悟朗, 坂本祥哉, 池田啓祐, CHI Z., WAN Y., 鈴木雅弘, 田中新, 酒巻真粧子, 雨宮健太, 田中雅明, 田中雅明, 中根了昌, 藤森淳

    日本物理学会講演概要集(CD-ROM)　73　(2)　2018

    ISSN： 2189-079X

  6. 磁場角度依存X線磁気円二色性によるSi基板上に作製したCoFe2O4/Al2O3極薄膜の界面付近の磁気異方性の評価

    野中洋亮, 若林勇希, 芝田悟朗, 坂本祥哉, 池田啓祐, 池震棟, WAN Yuxuan, 鈴木雅弘, 田中新, 田中雅明, 田中雅明, 中根了昌, 藤森淳

    KEK Progress Report (Web)　(2018-7)　2018

    ISSN： 1344-6320

  7. Thickness dependent change of the magnetic anisotropy of CoFe2O4 thin films

    野中洋亮, 若林勇希, 芝田悟朗, 坂本祥哉, 池田啓祐, 池震棟, 万宇軒, 鈴木雅弘, 酒巻真粧子, 雨宮健太, 田中雅明, 中根了昌, 藤森淳

    量子ビームサイエンスフェスタ(Web)　2017　2018

  8. La1-xSrxMnO3薄膜における基板応力により誘起された異方的スピン分布の角度依存X線磁気円二色性による観測

    芝田悟朗, 北村未歩, 簑原誠人, 吉松公平, 吉松公平, 門野利治, 石上啓介, 原野貴幸, 高橋文雄, 坂本祥哉, 野中洋亮, 池田啓祐, CHI Zhendong, 古瀬充穂, 淵野修一郎, 岡野眞, 藤平潤一, 内田公, 渡邊和訓, 藤平秀幸, 藤平誠一, 田中新, 組頭広志, 小出常晴, 藤森淳

    Photon Factory News　36　(3)　2018

    ISSN： 0916-0604

  9. X線磁気円二色性によるL10秩序型FePt薄膜の磁気異方性の研究

    池田啓祐, 芝田悟朗, 関剛斎, 石上啓介, 堀尾眞史, 坂本祥哉, 野中洋亮, 酒巻真粧子, 雨宮健太, 河村直己, 鈴木基寛, 高梨弘毅, 藤森淳

    応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017

    ISSN： 2436-7613

  10. Si(111)基板上に作製したスピネルフェライトCoFe2O4薄膜の角度依存XMCD

    野中洋亮, 若林勇希, 芝田悟朗, 竹田幸治, 坂本祥哉, 池田啓祐, CHI Z., 田中新, 斎藤祐児, 山上浩志, 酒巻真粧子, 雨宮健太, 田中雅明, 中根了昌, 藤森淳

    日本物理学会講演概要集(CD-ROM)　72　(2)　2017

    ISSN： 2189-079X

  11. 軟X線角度分解光電子分光による強磁性半導体Ge1-xFexの電子構造の解明

    坂本祥哉

    日本放射光学会誌　29　(2)　104-105　2016/03

  12. 19pBM-3 Angle dependent x-ray magnetic circular dichroism study of the spinel-type vanadate CoV_2O_4

    Nonaka Y., Shibata G., Koborinai R., Ishigami K., Sakamoto S., Ikeda K., Chi Z., Koide T., Tanaka A., Katsufuji T., Fujimori A.

    Meeting Abstracts of the Physical Society of Japan　71　2021-2021　2016

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.71.1.0_2021 　

    ISSN： 2189-079X

  13. Pt L2,3端XMCDにより観測したL10秩序型FePt薄膜の磁気モーメントの異方性

    池田啓祐, 芝田悟朗, 関剛斎, 石上啓介, 堀尾眞史, 坂本祥哉, 野中洋亮, 河村直己, 鈴木基寛, 高梨弘毅, 藤森淳

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)　77th　2016

    ISSN： 2436-7613

  14. 軟X線角度分解光電子分光による強磁性半導体Ge1-xFexの電子構造の解明

    坂本祥哉, 若林勇希, 竹田幸治, 藤森伸一, 鈴木博人, 伴芳祐, 山上浩志, 山上浩志, 田中雅明, 大矢忍, 藤森淳

    日本放射光学会年会・放射光科学合同シンポジウム予稿集　29th　2016

  15. 21pBA-8 ARPES and core-level spectroscopies of the coexistence of ferromagnetism and superconductivity in Sr_2VFeAsO_<3-δ>

    Horio M., Katagiri T., Namiki H., Okazaki K., Suzuki H., Xu J., Koshiishi K., Ishigami K., Shibata G., Takahashi Y., Sakamoto S., Nonaka Y., Ono K., Horiba K., Kobayashi M., Minohara M., Sakai E., Koide T., Kumigashira H., Sasagawa T., Fujimori A.

    Meeting Abstracts of the Physical Society of Japan　70　1994-1994　2015

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.70.1.0_1994 　

    ISSN： 2189-079X

  16. 21pAH-7 Field direction dependence of x-ray magnetic circular dichroism in the magnetite Fe_3O_4 thin film

    Nonaka Y., Shibata G., Chang Chun-Fu, Liu Xiongha, Ishigami K., Sakamoto S., Tanaka A., Koide T., Tjeng Liu Hao, Fujimori A.

    Meeting Abstracts of the Physical Society of Japan　70　1070-1070　2015

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.70.1.0_1070 　

    ISSN： 2189-079X

  17. 18pCM-13 Resonant inelastic soft X-ray scattering study of the new diluted magnetic semiconductor Ba1-xKx(Zn1-yMny)2As2

    Suzuki H., Okamoto J., Zhao G. Q., Sakamoto S., Chen Z. Y., Wu W. B., Zhao K., Chen B. J., Gu Bo, Maekawa S., Tanaka A., Uemura Y. J., Jin C. Q., Chen C. T., Huang D. J., Fujimori A.

    Meeting Abstracts of the Physical Society of Japan　70　965-965　2015

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.70.2.0_965 　

    ISSN： 2189-079X

  18. 18pPSA-3 Angle dependent x-ray magnetic circular dichroism of the magnetite Fe3O4 thin film

    Nonaka Y., Shibata G., Chang Chun-Fu, Liu Xiongha, Ishigami K., Sakamoto S., Ikeda K., Tanaka A., Koide T., Tjeng Liu Hao, Fujimori A.

    Meeting Abstracts of the Physical Society of Japan　70　1255-1255　2015

    Publisher: The Physical Society of Japan (JPS)

    DOI： 10.11316/jpsgaiyo.70.2.0_1255 　

    ISSN： 2189-079X

  19. 角度依存XMCDによるLa0.6Sr0.4MnO3薄膜の磁気異方性とスピン分布異方性の観測

    芝田悟朗, 吉松公平, 石上啓介, 原野貴幸, 高橋文雄, 坂本祥哉, 門野利治, 古瀬充穂, 淵野修一郎, 岡野眞, 藤平潤一, 内田公, 渡邊和訓, 藤平秀幸, 藤平誠一, 組頭広志, 組頭広志, 小出常晴, 藤森淳

    日本物理学会講演概要集(CD-ROM)　70　(2)　2015

    ISSN： 2189-079X

  20. 10aBH-1 X-ray magnetic circular and linear dichroism of the spinel-type oxide CoV_2O_4

    Nonaka Y., Shibata G., Koborinai R., Ishigami K., Sakamoto S., Tanaka A., Koide T., Katsufuji T., Fujimori A.

    Meeting abstracts of the Physical Society of Japan　69　(2)　452-452　2014/08/22

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  21. 28aCE-6 ARPES and XMCD studies of the coexistence of ferromagnetism and superconductivity in Sr_2VFeAsO_<3-δ>

    Horio M., Okazaki K., Suzuki H., Xu J., Ishigami K., Takahashi Y., Shibata G., Sakamoto S., Fujimori A., Kumigashira H., Ono K., Koide T., Katagiri T., Sasagawa T.

    Meeting abstracts of the Physical Society of Japan　69　(1)　586-586　2014/03/05

    Publisher: The Physical Society of Japan (JPS)

    ISSN： 1342-8349

  22. 強磁性と超伝導が共存するSr2VFeAsO3-δのARPESとXMCD

    堀尾眞史, 岡崎浩三, 片桐隆雄, 鈴木博人, 徐健, 石上啓介, 高橋文雄, 芝田悟朗, 坂本祥哉, 小野寛太, 組頭広志, 小出常晴, 笹川崇男, 藤森淳

    物構研サイエンスフェスタ要旨集　2013　2014

  23. 強磁性半導体(In,Fe)As:Beの磁化過程のXMCDによる研究

    坂本祥哉, LE Duc Anh, PHAM Nam Hai, 芝田悟朗, 高橋文雄, 小林正起, 竹田幸治, 山上浩志, 山上浩志, 斎藤祐児, 小出常晴, 田中雅明, 藤森淳

    物構研サイエンスフェスタ要旨集　2013　2014

  24. 30aAY-1 Photoemission and X-ray magnetic circular dichroism study of a new diluted magnetic semiconductor Ba_<1-y>K_y(Zn_<1-x>Mn_x)_2As_2

    Suzuki H, Huang D. J, Chen C. T, Zhao K, Jin C. Q, Gu Bo, Maekawa S, Uemura Y. J, Shibata G, Takahashi Y, Sakamoto S, Yoshimatsu K, Kumigashira H, Fujimori A, Chang F.-H, Lin H.-J

    Meeting Abstracts of the Physical Society of Japan　69　(0)　904-904　2014

    Publisher: 一般社団法人 日本物理学会

    ISSN： 1342-8349

  25. 強磁性半導体(In,Fe)AsのXMCD測定

    坂本祥哉, 芝田悟朗, 高橋文雄, 藤森淳, 小出常晴, 小林正紀, 竹田幸治, 山上浩志, 山上浩志, 斎藤祐児, ANH Le Duc, HAI Pham Nam, 田中雅明

    日本物理学会講演概要集　68　(2)　2013

    ISSN： 1342-8349

Show all ︎Show first 5

Presentations 44

  1. Mn3Snエピタキシャル薄膜のX線磁気円二色性とスピントルクダイオード効果

    坂本祥哉

    金研合同セミナー ノンコリニア磁性とトポロジーの物理と応用　2025/01

  2. X線磁気円二色性によるMn3Sn薄膜のバルクと表面の磁気構造の研究

    坂本祥哉, 肥後友也, 小谷佳範, 甲崎秀俊, 中村哲也, 中辻知, 三輪真嗣

    第38回日本放射光学会年会・放射光科学合同シンポジウム　2025/01

  3. Spin-torque diode effect in a noncollinear antiferromagnet Mn3Sn

    S. Sakamoto, T. Nomoto, T. Higo, Y. Hibino, T. Yamamoto, S. Tamaru, Y. Kotani, H. Kosaki, M. Shiga, D. Nishio-Hamane, T. Nakamura, T. Nozaki, K. Yakushiji, R. Arita, S. Nakatsuji, S. Miwa

    KiPAS international workshop on Recent Advances in Orbitronics and Spintronics　2024/11

  4. 放射光でみるスピントロニクス薄膜 Invited

    坂本祥哉

    物性科学の新展開　2024/09

  5. Microwave control of chiral spin rotation in a non-collinear antiferromagnet Mn3Sn

    S. Sakamoto, T. Nomoto, T. Higo, Y. Hibino, T. Yamamoto, S. Tamaru, Y. Kotani, H. Kosaki, M. Shiga, D. Nishio-Hamane, T. Nakamura, T. Nozaki, K. Yakushiji, R. Arita, S. Nakatsuji, S. Miwa

    2024/09

  6. Spin-torque-driven magnetic resonance in a chiral antiferromagnet Mn3Sn Invited

    S. Sakamoto, T. Nomoto, T. Higo, Y. Hibino, T. Yamamoto, S. Tamaru, Y. Kotani, H. Kosaki, M. Shiga, D. Nishio-Hamane, T. Nakamura, T. Nozaki, K. Yakushiji, R. Arita, S. Nakatsuji, S. Miwa

    The 5th International Symposium on Advanced Magnetic Materials and Applications (ISAMMA)　2024/08

  7. Electrical control and detection of chiral spin rotation in Mn3Sn

    S. Sakamoto, T. Nomoto, T. Higo, Y. Hibino, T. Yamamoto, S. Tamaru, Y. Kotani, H. Kosaki, M. Shiga, D. Nishio-Hamane, T. Nakamura, T. Nozaki, K. Yakushiji, R. Arita, S. Nakatsuji, S. Miwa

    25th International Colloquium on Magnetic Films and Surfaces (ICMFS2024)　2024/07

  8. Two-dimensional imaging of spin and orbital magnetic moments in ultra-thin Co films by soft x-ray ptychography

    S. Sakamoto, Y. Takeo, N. Furuya, K. Sakurai, K. Yoshinaga, A. Suzuki, I. Matsuda, Y. Harada, T. Kimura, S. Miwa

    2024/03

  9. Surface and bulk magnetic structure of Mn3Sn epitaxial thin films studied by x-ray magnetic circular dichroism

    S. Sakamoto, T. Higo, Y. Kotani, H. Kosaki, M. Shiga, D. Nishio-Hamane, T. Nakamura, S. Nakatsuji, S. Miwa

    International Symposium on Quantum Electronics　2024/02

  10. 軟X線磁気円二色性によるスピントロニクス薄膜の磁性と電子構造の研究 Invited

    坂本祥哉

    第28回日本放射光学会　2024/01

  11. Orbital Polarization Enhanced by Electron Correlationat the Fe/MgO Interafce: a Depth-resolved X-ray Magnetic Circular Dichroism Study

    S. Sakamoto, M. Tsujikawa, M. Shirai, K. Amemiya, S. Miwa

    INTERMAG 2023　2023/05

  12. X-ray magnetic circular dichroism in the chiral antiferromagnet Mn3Sn epitaxial thin films

    S. Sakamoto, T. Higo, M. Shiga, K. Amemiya, S. Nakatsuji, S. Miwa

    Spin-RNJ Symposium 2022　2023/03

  13. Increased orbital magnetic moment and perpendicular magnetic anisotropies at the Fe/LiF interface

    S. Sakamoto, T. Nozaki, S. Yuasa, K. Amemiya, S. Miwa

    2023/03

  14. Giant orbital polarization at the Fe/MgO interface probed by depth-resolved x-ray magnetic circular dichroism

    S. Sakamoto, M. Tsujikawa, M. Shirai, K. Amemiya, S. Miwa

    2nd international symposium on trans-scale quantum science TSQS 2022 hybrid conference　2022/11

  15. カイラル反強磁性体Mn3Sn薄膜における自発的X線磁気円二色性 Invited

    坂本祥哉, 肥後友也, 志賀雅亘, 雨宮健太, 中辻知, 三輪真嗣

    日本放射光学会 第14回若手研究会 次世代放射光で切り拓く軟X線科学　2022/09

  16. Spontaneous x-ray magnetic circular dichroism in the antiferromagnetic Mn3Sn epitaxial thin film

    S. Sakamoto, T. Higo, M. Shiga, K. Amemiya, S. Nakatsuji, S. Miwa

    24th International Colloquium on Magnetic Films and Surfaces　2022/07

  17. Observation of spontaneous x-ray magnetic circular dichroism in the antiferromagnetic Mn3Sn thin film

    S. Sakamoto, T. Higo, M Shiga, K. Amemiya, S. Nakatsuji, S. Miwa

    2022/03

  18. X線磁気円二色性で見るスピントロニクス薄膜 Invited

    坂本祥哉

    第8回量子物質ランチョンセミナー（オンライン）　2022/01

  19. Depth profile of the Fe spin and orbital magnetic moments in a V/Fe/MgO trilayer revealed by depth-resolved x-ray magnetic circular dichroism

    S. Sakamoto, M. Tsujikawa, M. Shirai, K. Amemiya, S. Miwa

    2021/03

  20. Momentum- and band-dependent coherent-phonon response in Sb(111) surface

    S. Sakamoto, J. A. Sobota, P. S. Kirchmann, Z.-X. Shen

    2020/06

  21. Anisotropic distribution of the Mn 3d spins in the ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 revealed by angle-dependent XMCD”, New Perspective in Spin Conversion Science (NPSCS2020)

    S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    New Perspective in Spin Conversion Science (NPSCS2020)　2020/02

  22. Origin of Perpendicular Magnetic Anisotropy of the Ferromagnetic Semiconductor (Ba,Zn)(Zn,Mn)2As2: Angle-dependent XMCD Study

    S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    64th Annual Conference on Magnetism and Magnetic Materials　2019/11

  23. Large perpendicular magnetic anisotropy and anisotropic electronic structure of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 single crystal studied by angle-dependent x-ray magnetic circular dichroism

    S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    APS March Meeting　2019/03

  24. XMCDによるFeドープ強磁性半導体の磁化過程の研究

    坂本祥哉, Le Duc Anh, Nguyen Thanh Tu, Pham Nam Hai, 竹田幸治, 小林正起, 中根了昌, 芝田悟朗, 若林勇希, 高橋文雄, 野中洋亮, 池田啓祐, 池震棟, 万宇軒, 鈴木雅弘, 斎藤祐児, 山上浩志, 小出常晴, 田中雅明, 藤森淳

    スピントロニクス学術研究基盤と連携ネットワークシンポジウム　2018/03

  25. XMCD studies of the magnetization process of the Fe-doped ferromagnetic semiconductors

    S.Sakamoto, L. D. Anh, P. N. Hai, Y. Takeda, M. Kobayashi, R. Nakane, Y. K. Wakabayashi, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, Y. Saitoh, H. Yamagami, M. Tanaka, A. Fujimori

    2018/03

  26. 光電子分光、XMCD、第一原理計算から見たFeドープ強磁性半導体 Invited

    坂本祥哉

    第１回CSRN-Tokyo Workshop 2017 新しいスピントロニクス機能材料の開発とその物性制御　2017/10

  27. Large perpendicular magnetic anisotropy of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 single crystal

    S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    2017/09

  28. XMCD study on large perpendicular magnetic anisotropy of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 single crystal

    S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, A. Fujimori

    Junjiro Kanamori Memorial International Symposium　2017/09

  29. Soft x-ray spectroscopy and first-principles calculation studies of the electronic structure of the novel high-TC ferromagnetic semiconductor (Ga,Fe)Sb

    S. Sakamoto, N. T. Tu, Y. Takeda, S.-i. Fujimori, P. N. Hai, L. D. Anh, Y. K. Wakabayashi, G. Shibata, M. Horio, K. Ikeda, Y. Saitoh, H. Yamagami, M. Tanaka, A. Fujimori

    INTERMAG 2017　2017/04

  30. Feをドープした半導体の電子構造と強磁性発現機構 Invited

    坂本祥哉

    科学研究費基盤A研究会 酸化物薄膜界面の異方的磁性とスピン-軌道結合現象の多自由度放射光分光　2017/03

  31. Electronic structure of the novel high-TC ferromagnetic semiconductor (Ga,Fe)Sb

    S. Sakamoto, N. T. Tu, Y. Takeda, S.-i. Fujimori, P. N. Hai, L. D. Anh, Y. K. Wakabayashi, G. Shibata, M. Horio, K. Ikeda, Y. Saitoh, H. Yamagami, M. Tanaka, A. Fujimori

    The 37th REIMEI Workshop on Frontiers of Correlated Quantum Matters and Spintronics　2017/01

  32. Electronic Structure of the p-type Ferromagnetic Semiconductor (Ga,Fe)Sb

    S. Sakamoto, N. T. Tu, Y. Takeda, S.-i. Fujimori, P. N. Hai, L. D. Anh, Y. K. Wakabayashi, G. Shibata, M. Horio, K. Ikeda, Y. Saitoh, H. Yamagami, M. Tanaka, A. Fujimori

    2016/09

  33. Electronic structure of the ferromagnetic semiconductor Ge1-xFex revealed by soft x-ray angle-resolved photoemission spectroscopy

    S. Sakamoto, Y. K. Wakabayashi, Y. Takeda, S.-i. Fujimori, H. Suzuki, Y. Ban, H. Yamagami, M. Tanaka, S. Ohya, A. Fujimori

    9th International Conference on Physics and Applications of Spin-Related Phenomena in Solids　2016/08

  34. Electronic Structure of Ferromagnetic Semiconductor Ge1-xFex Studied by Soft X-ray Angle-Resolved Photoemission Spectroscopy

    S. Sakamoto, Y. K. Wakabayashi, Y. Takeda, S.-i. Fujimori, H. Suzuki, Y. Ban, H. Yamagami, M. Tanaka, S. Ohya, A. Fujimori

    The 16th Japan-Korea-Taiwan Workshop on Strongly Correlated Electron Systems　2016/02

  35. 軟X線角度分解光電子分光による強磁性半導体Ge1-xFexの電子構造の解明

    坂本祥哉, 若林勇希, 竹田幸治, 藤森伸一, 鈴木博人, 伴芳祐, 山上浩志, 田中雅明, 大矢忍, 藤森淳

    第29回放射光学会年会・放射光科学合同シンポジウム JSR2016　2016/01

  36. 軟X線角度分解光電子分光による強磁性半導体Ge1-xFexの電子構造の解明

    坂本祥哉, 若林勇希, 竹田幸治, 藤森伸一, 鈴木博人, 伴芳祐, 山上浩志, 田中雅明, 大矢忍, 藤森淳

    第20回半導体スピン工学の基礎と応用PASPS-20　2015/12

  37. Electronic Structure of Ferromagnetic Semiconductor Ge1-xFex Studied by Soft X-ray Angle Resolved Photoemission Spectroscopy

    S. Sakamoto, Y. Wakabayashi, Y. Takeda, S.-i. Fujimori, H. Suzuki, H. Yamagami, M. Tanaka, S. Ohya, A. Fujimori

    2015/03

  38. n型強磁性半導体(In,Fe)As:BeのXMCDによる磁化過程の研究

    坂本祥哉, Le Duc Anh, Pham Nam Hai, 芝田悟朗, 竹田幸治, 高橋文雄, 小出常晴, 田中雅明, 藤森淳

    第19回半導体スピン工学の基礎と応用PASPS-19　2014/12

  39. Magnetization Process of the n-type Ferromagnetic Semiconductor (In,Fe)As:Be Studied by X-ray Magnetic Circular Dichroism

    S. Sakamoto, L. D. Anh, P. N. Hai, G. Shibata, Y. Takahashi, Y. Takeda, M. Kobayashi, T. Koide, M. Tanaka, A. Fujimori

    2014/09

  40. XMCD study of the magnetization process in the ferromagnetic semiconductor (In,Fe)As:Be

    2014/03

  41. XMCD study of the n-type high-TC ferromagnetic semiconductor (In,Fe)As:Be

    S. Sakamoto, L. D. Anh, P. N. Hai, G. Shibata, Y. Takahashi, M. Kobayashi, T. Koide, Y. Takeda, H. Yamagami, Y. Saitoh, M. Tanaka, A. Fujimori

    The 6th Indo-Japan Seminar, Physics of Multi-Functional Correlated Materials　2014/03

  42. XMCD measurements of ferromagnetic semiconductor (In,Fe)As

    2013/12

  43. 強磁性半導体(In,Fe)AsのXMCD測定

    坂本祥哉, 芝田悟朗, 高橋文雄, 藤森淳, 小出常晴, 小林正起, 竹田幸治, 山上浩志, 斎藤祐児, Le Duc Anh, Pham Nam Hai, 田中雅明

    日本物理学会2013年秋季大会　2013/09

  44. XMCD study of the n-type high-TC ferromagnetic semiconductor (In,Fe)As:Be

    S. Sakamoto, M. Kobayashi, G. Shibata, Y. Takahashi, A. Fujimori, T. Koide, Y. Takeda, Y. Saitoh, H. Yamagami, L. D. Anh, P. N. Hai, M. Tanaka

    2014 Quantum Materials Symposium

Show all Show first 5

Research Projects 5

  1. Visualizing spin and orbital current by soft x-ray ptychography

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: The University of Tokyo

    2023/04/01 - 2026/03/31

  2. 反強磁性金属における自励発振の研究

    三輪 真嗣, 坂本 祥哉, 野本 拓也

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(A)

    Institution: 東京大学

    2022/04/01 - 2025/03/31

  3. Improving perpendicular magnetic anisotropy of Fe/MgO and its voltage controllability by introducing nonmagnetic elements

    Sakamoto Shoya

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Early-Career Scientists

    Institution: The University of Tokyo

    2020/04/01 - 2022/03/31

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    In this project, we aimed to improve the magnetic anisotropy of Fe/MgO-based systems and its sensitivity to voltage application by introducing nonmagnetic metal elements. First, we examined how electrons behave at the Fe/MgO interface by performing synchrotron spectroscopy measurements and obtained new insights into the origin of magnetic anisotropy in Fe/MgO systems. Next, we doped V or Al in Fe/MgO to modify the position of the Fermi level or the electronic structure. We find that V doping, which introduce electrons to the system, can increase the sensitivity of magnetic anisotropy to the voltage application.

  4. 鉄をドープした強磁性半導体の電子構造と強磁性発現機構の解明

    坂本 祥哉

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 東京大学

    2017/04/26 - 2019/03/31

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    本研究では、Feをドープした新しい強磁性半導体の電子構造と強磁性発現の機構を解明することを目的とした。従来までのMnをベースとした強磁性半導体は、p型の電気伝導しか実現できないことや、強磁性転移温度が室温より低いという問題を抱えていた。Feをドープした系では、p型だけでなく、n型や絶縁的な強磁性半導体が実現できる。また、(Ga,Fe)Sbや(In,Fe)Sbといった物質で、室温より高い強磁性転移温度が報告され注目を集めている。 2017年度は、これまでに研究してきた(In,Fe)As:Be、Ge:Feに加え、(Ga,Fe)Sbと(Al,Fe)Sbに対してX線磁気円二色性(XMCD)、共鳴光電子分光実験を行った。さらに第一原理計算も系統的に行った。 共鳴光電子分光の実験では、Feの2p-3d吸収端において大きなオージェピークが観測され、Feの3d電子が遍歴性を持つことがわかった。またフェルミ準位においても、光電子スペクトルの共鳴増大が観測され、Feの3d状態がフェルミ準位に存在することがわかった。XMCD実験では、Feの2p-3d吸収端において大きなXMCD信号が観測され、この物質の磁性がFeに由来することが確認された。XMCDから求めた磁化は強磁性転移温度以上でも磁場に強く応答し、高温でもナノスケールの強磁性領域が存在することが明らかになった。この原因はFe原子が空間的に不均一に分布しているためと考えられる。第一原理計算からは、Feが3価であるという当初の予想に反し、Feの3d電子数が6であることが示唆された。これは、Sb系の半導体の価電子帯のエネルギーが高いために、電子が価電子帯に存在するより、3d軌道を占有した方がエネルギー的に安定であるためと考えらえる。また、このような状況で特に高い強磁性転移温度が実現していることから、この6つ目の電子が強磁性発現の鍵であると結論した。

  5. Magnetic anisotropy and electron orbitals in magnetic thin films and multilayers studied by angle-dependent x-ray magnetic circular dichroism

    Shibata Goro, SAKAMOTO Shoya, NONAKA Yosuke, IKEDA Keisuke, CHI Zhendong, WAKABAYASHI Yuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (B)

    Institution: The University of Tokyo

    2015/04/01 - 2018/03/31

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    In the present research project, we have worked on the improvement of the vector-magnet apparatus for x-ray dichroism spectroscopy, which has allowed us to perform angle-dependent x-ray magnetic circular dichroism (XMCD) experiments with higher precision than before. We have also established a methodology to investigate the electron orbital occupation in ferromagnets using this method. We have performed angle-dependent XMCD experiments on several ferromagnets such as (La,Sr)MnO3 and L10-type FePt, which are candidates for spintronics materials. We have experimentally demonstrated that, in order to explain the magnetic anisotropy of ferromagnetic thin films, one has to take into account the anisotropy of the electron-density distribution in addition to the anisotropy of the orbital magnetic moment.