Ultrafast manipulation of magnetization with optical or lattice-wave excitations and its applications

2015 Fiscal Year Final Research Report

• Project/Area Number: 22226002
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Munekata Hiro 東京工業大学, 像情報工学研究所, 教授 (60270922)
• Co-Investigator(Renkei-kenkyūsha): KITAMOTO Yoshitaka 東京工業大学, 総合理工学研究科(研究院), 教授 (10272676) ; NISHIBAYASHI Kazuhiro 東京工業大学, 像情報工学研究所, 研究員(特任講師) (20361181)
• Project Period (FY): 2010-04-01 – 2016-03-31
• Keywords: 光励起 / 磁化才差運動 / 超高速現象 / コヒーレント制御 / 強磁性半導体 / 界面強磁性積層膜 / 導波路 / スピンフォトニクス

Outline of Final Research Achievements

Manipulation of magnetization with femotosecond laser pulses has been studied in order to find ways to break the two-picosecond (ps) limit shown by magnetic pulses. The photo-excited precession of magnetization (PEPM) in ferromagnetic semiconductors is found to be attributed to the change in magnetic anisotropy due to photo-ionization of Mn ions, with which non-linear control of the precession amplitude has also been demonstrated by a pair of sub-ps-separated laser pulses. Furthermore, PEPM with MW/cm2 pulse power has been found possible in the Co-Pd multilayers, which indicates the discovery of candidate materials for spin-photonic devices. The spatial de-multiplexing of polarization modulated signals has been demonstrated using the optical fibers attached with magnetic thin films, through which fundamentals of spin-photonic devices are experimented. Helicity switching of circular polarized light at 100 kHz has been demonstrated at room temperature by dual-injection spin-LED.

Free Research Field

スピントロニクス