X-ray-induced spin-polarized states and ultrafast magnetization dynamics

• Project/Area Number: 17H02823
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Quantum beam science
• Research Institution: Japan Synchrotron Radiation Research Institute
• Principal Investigator: Suzuki Motohiro 公益財団法人高輝度光科学研究センター, 分光・イメージング推進室, 主席研究員 (60443553)
• Co-Investigator(Kenkyū-buntansha): 田中 義人 兵庫県立大学, 物質理学研究科, 教授 (80260222)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥10,010,000 (Direct Cost: ¥7,700,000、Indirect Cost: ¥2,310,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2017: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
• Keywords: X線自由電子レーザー / 磁気ダイナミクス / 超高速現象 / X線誘起現象 / 光磁気記録 / Ｘ線自由電子レーザー / 放射光 / 自由電子レーザー / 超高速磁気ダイナミクス / 磁気光学効果

Outline of Final Research Achievements

Circularly-polarized X-ray free-electron laser (XFEL) pulses are used to modify the magnetic states of the sample instantaneously. We developed an original time-resolved magnetic microscopy technique with the XFEL-pump and laser-probe scheme. The experiment using an iron garnet sample demonstrated the XFEL-induced demagnetization within one picosecond (one-trillionth of a second). The ultrafast change in magnetism associated with X-ray core-excitation was first observed.

Academic Significance and Societal Importance of the Research Achievements

磁性の源である電子スピンの状態を非常に短い時間で観測することで、磁性が生じるメカニズムを詳細に調べることができる。本研究では、超短パルスＸ線自由電子レーザー光を磁性体に照射することで磁性体試料の磁気状態を瞬間的に改変し、１ピコ秒（ピコは１兆分の１）以下の時間での磁性の変化を観測した。X線照射による磁性制御に初めて成功するとともに、将来の超高速磁気記録につながる原理解明を行った。

Research Products

• [Journal Article] Magnetic Microscopy Using a Circularly Polarized Hard-X-ray Nanoprobe at SPring-8 (2020)
  • Author(s): Suzuki M.、Yumoto H.、Koyama T.、Yamazaki H.、Takeuchi T.、Kawamura N.、Mizumaki M.、Osawa H.、Kondo Y.、Ariake J.、Yasui A.、Kotani Y.、Tsuji N.、Nakamura T.、Hirosawa S.、Yamada K. T.、Kim S.、Kim K.-J.、Ishibashi M.、Ono T.、Ohashi H.
  • Journal Title: Synchrotron Radiation News Volume: 33 Issue: 2 Pages: 4-11
  • DOI: 10.1080/08940886.2020.1725795
• [Journal Article] Polarization control with an X-ray phase retarder for high-time-resolution pump-probe experiments at SACLA (2019)
  • Author(s): Kubota Y.、Suzuki M.、Katayama T.、Yamamoto K.、Tono K.、Inubushi Y.、Seki T.、Takanashi K.、Wadati H.、Yabashi M.
  • Journal Title: Journal of Synchrotron Radiation Volume: 26 Issue: 4 Pages: 1139-1143
  • DOI: 10.1107/s1600577519006222
  • Peer Reviewed / Open Access
• [Journal Article] Ultrafast demagnetization of Pt magnetic moment in L10-FePt probed by magnetic circular dichroism at a hard x-ray free electron laser (2019)
  • Author(s): Yamamoto Kohei、Kubota Yuya、Suzuki Motohiro、Hirata Yasuyuki、Carva Karel、Berritta Marco、Takubo Kou、Uemura Yohei、Fukaya Ryo、Tanaka Kenta、Nishimura Wataru、Ohkochi Takuo、Katayama Tetsuo、他8名
  • Journal Title: New Journal of Physics Volume: 21 Issue: 12 Pages: 123010-123010
  • DOI: 10.1088/1367-2630/ab5ac2
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] X線トモグラフィを用いた磁気微粒子の3次元観測 (2019)
  • Author(s): 鈴木基寛
  • Journal Title: 応用物理 Volume: 88 Pages: 198-202
  • NAID: 130007709441
  • Peer Reviewed
• [Journal Article] Time-resolved optical spectroscopy of a GaAs single crystal irradiated by SR X-ray pulses (2019)
  • Author(s): Tanaka Yoshihito, Nagashima Maki, Tanaka Kenta, Hasegawa Takayuki, Fukuyama Yoshimitsu, Yasuda Nobuhiro
  • Journal Title: AIP conference proceedings Volume: 2054 Pages: 040009-040009
  • DOI: 10.1063/1.5084610
  • Peer Reviewed
• [Journal Article] Three-dimensional visualization of magnetic domain structure with strong uniaxial anisotropy via scanning hard X-ray microtomography (2018)
  • Author(s): Motohiro Suzuki1, Kab-Jin Kim, Sanghoon Kim, Hiroki Yoshikawa, Takayuki Tono, Kihiro T. Yamada, Takuya Taniguchi, Hayato Mizuno, Kent Oda, Mio Ishibashi, Yuushou Hirata, Tian Li, Arata Tsukamoto, Daichi Chiba, and Teruo Ono
  • Journal Title: Appl. Phys. Express Volume: 11 Issue: 3 Pages: 036601-036601
  • DOI: 10.7567/apex.11.036601
  • NAID: 120006466610
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] XFEL照射により誘起される希土類鉄ガーネットの超高速磁気ダイナミクス (2020)
  • Author(s): 鈴木基寛、西村渉、岡部純幸、近藤啓介、小倉弓枝、片山哲夫、佐藤尭洋、久保田雄也、富樫格、松田巌、田中義人
  • Organizer: 日本物理学会 第75回年次大会
• [Presentation] XFELポンプ-可視光プローブ時間分解磁気顕微鏡の開発とXFEL誘起磁気ダイナミクスの解析 (2020)
  • Author(s): 西村渉、岡部純幸、近藤啓介、小倉弓枝、片山哲夫、佐藤尭洋、久保田雄也、富樫格、松田巌、田中義人、鈴木基寛
  • Organizer: 日本物理学会 第75回年次大会
• [Presentation] Three-dimensional observation of magnetic domain structure by scanning hard X-ray microtomography (2019)
  • Author(s): Motohiro Suzuki
  • Organizer: The 15th Symposium of Japanese Research Community on X-ray Imaging Optics (XIO2019)
  • Int'l Joint Research / Invited
• [Presentation] 硬X線MCDトモグラフィーによる磁区構造の３次元観察 (2019)
  • Author(s): 鈴木基寛
  • Organizer: 第32回日本放射光学会年会・放射光化学合同シンポジウム
  • Invited
• [Presentation] Time-resolved optical spectroscopy of a GaAs single crystal irradiation by SR X-ray pulses (2018)
  • Author(s): Y. Tanaka, M. Nagashima, K. Tanaka, T. Hasegawa, Y. Fukuyama, N. Yasuda
  • Organizer: SRI2018 (Synchrotron Radiation Instrumentation)
  • Int'l Joint Research
• [Presentation] Three-Dimensional Observation of Magnetic Domain Structure Using Scanning Hard X-ray Microtomography (2018)
  • Author(s): Motohiro Suzuki, Kab-Jin Kim, Sanghoon Kim, Hiroki Yoshikawa, Takayuki Tono, Kihiro T. Yamada, Takuya Taniguchi, Hayato Mizuno, Kento Oda, Mio Ishibashi, Yuushou Hirata, Tian Li, Arata Tsukamoto, Daichi Chiba, and Teruo Ono
  • Organizer: 2018 Korean Physical Society Fall Meeting
  • Invited
• [Presentation] 放射光パルスX線照射下のGaAs単結晶の時間分解近赤外分光 (2018)
  • Author(s): 永島麻紀，田中健太，福山祥光，安田伸広，長谷川尊之，田中義人
  • Organizer: 第31回日本放射光学会年会・放射光科学合同シンポジウム
• [Presentation] X線自由電子レーザーでの円偏光利用と展望 (2017)
  • Author(s): 鈴木基寛
  • Organizer: 日本物理学会2017年秋季大会
  • Invited
• [Presentation] 放射光XMCD分光によるスピントロニクス材料の微視的機構の研究 (2017)
  • Author(s): 鈴木基寛
  • Organizer: 第33回日本磁気学会光機能磁性デバイス・材料専門研究会
  • Invited