[23a-A205-1~13] 10.2 Fundamental and exploratory device technologies for spin

[23a-A205-7] Effect of non-Markovian damping on ultrafast spin dynamics

〇Hiroshi Imamura¹, Hiroko Arai¹, Rie Matsumoto¹, Toshiki Yamaji¹, Hiroshi Tsukahara^1,2 (1.AIST, 2.Osaka Univ.)

Keywords:ultrafast spin dynamics, non-Markovian damping, LLG equation

Recent advances in experimental techniques have made it possible to manipulate and measure magnetization dynamics on femtosecond time scales. This time scale is comparable to the correlation time of a heat bath felt by spins, and the magnetization motion is described by an equation of motion with non-Markovian relaxation. We derived analytical expressions for the precessional angular velocity and the effective damping constant for arbitrary correlation times under the assumption that the Gilbert damping constant is small.