论文标题
Landau-Lifshitz-Bloch模型中的热波动
Thermal Fluctuations In The Landau-Lifshitz-Bloch Model
论文作者
论文摘要
提出了一种用于建模升高温度下磁化动力学的Landau Lifshitz Bloch方程的随机形式的热噪声的公式。热波动的扩散系数是通过fokker-plank方程获得定义自由能的平均场近似的。提出的模型导致平均磁化强度与小颗粒的平衡磁化一致。磁化幅度的分布是类似泊松的类型，而不是经典的玻尔兹曼分布。通过在高温下研究宏生颗粒中的平衡磁化来测试所提出的模型。该模型对多尺度建模有吸引力，例如建模热辅助磁记录系统和全光磁化逆转
A formulation for thermal noise in the stochastic form of the Landau Lifshitz Bloch equation used for modeling the magnetization dynamics at elevated temperatures is presented. The diffusion coefficients for thermal fluctuations are obtained via the Fokker-Plank equation using the mean field approximation of the field in defining the free energy. The presented model leads to a mean magnetization consistent with the equilibrium magnetization for small and large particles. The distribution of the magnetization magnitude is of a Poisson-like type rather than the classical Boltzmann distribution. The presented model was tested by studying the equilibrium magnetization in macrospin particles at high temperatures. The model is appealing for multi-scale modeling, such as modeling heat assisted magnetic recording systems and all-optical magnetization reversal
