[22p-A205-1~18] 10.2 スピン基盤技術・萌芽的デバイス技術

▲ [22p-A205-17] Time resolved state tomography for persistent coherence in Y₃Fe₅O₁₂

〇Tomosato Hioki^1,2、Takahiko Makiuchi²、Hiroki Shimizu²、Koujiro Hoshi^2,3、Mehrdad Elyasi¹、Kei Yamamoto⁴、Naoto Yokoi^2,3、Gerrit E.W. Bauer¹、Eiji Saitoh^2,1,3,4 (1.AIMR, Tohoku Univ.、2.Dept. Appl. Phys., UTokyo、3.Inst. AI and Beyond, UTokyo、4.JAEA)

キーワード：Magnetization dynamics, spintronics, magnon

Precessional motion of magnetization around the magnetic field decays to thermal equilibrium due to magnetization damping after cutting of the excitation force. After the decay, the phase coherence of the precession motion of magnetization was thought to be completely lost. Here we report the time-resolved magnetization dynamics measurement for a thin disk of yttrium iron garnet (YIG). We observed the prolonged coherence of the magnetization dynamics, which we call persistent coherence. Using newly developed time-resolved magnetization state tomography, we revealed that the temporal evolution of the persistent coherence exhibits two different time constant, which is supported by theoretical modelling. We will discuss the measurement method and detail of experimental results in the talk.