论文标题
光磁石材中的磁化动力学的非线性子开关制度
Nonlinear sub-switching regime of magnetization dynamics in photo-magnetic garnets
论文作者
论文摘要
我们在实验和数字上分析了钴型Yttrium铁石榴石膜中光诱导的相干磁化动力学的非线性状态。飞秒激光脉冲的照片磁激发揭示了自旋子系统的强烈非线性响应，有效的吉尔伯特阻尼显着增加。通过改变激光通量和外部磁场，我们表明这种非线性起源于磁能景观的非谐度。我们在数值上绘制了光磁开关阈值下方的非线性光诱导的自旋动力学的参数工作空间。通过对Landau-Lifshitz-Gilbert方程的数值模拟证实，我们的结果突出了磁性子系统在达到非线性自旋进液方向上的立方对称性的关键作用。这些发现扩展了对激光诱导的非线性自旋动力学的基本理解，并促进了应用光磁性的发展。
We analyze, both experimentally and numerically, the nonlinear regime of the photo-induced coherent magnetization dynamics in cobalt-doped yttrium iron garnet films. Photo-magnetic excitation with femtosecond laser pulses reveals a strongly nonlinear response of the spin subsystem with a significant increase of the effective Gilbert damping. By varying both laser fluence and the external magnetic field, we show that this nonlinearity originates in the anharmonicity of the magnetic energy landscape. We numerically map the parameter workspace for the nonlinear photo-induced spin dynamics below the photo-magnetic switching threshold. Corroborated by numerical simulations of the Landau-Lifshitz-Gilbert equation, our results highlight the key role of the cubic symmetry of the magnetic subsystem in reaching the nonlinear spin precession regime. These findings expand the fundamental understanding of laser-induced nonlinear spin dynamics as well as facilitate the development of applied photo-magnetism.
