Magnetization Dynamics Including Thermal Fluctuations: Basic Phenomenology, Fast Remagnetization Processes and Transitions Over High‐energy Barriers
Magnetization Dynamics Including Thermal Fluctuations: Basic Phenomenology, Fast Remagnetization Processes and Transitions Over High‐energy Barriers
复制标题
磁化动力学，包括热波动：基本现象学、快速重磁化过程和高能垒上的转变
DOI：
10.1002/9780470022184.hmm204
复制
发表时间：
2007
期刊：
影响因子：
41.2
通讯作者：
D. Berkov
中科院分区：
文献类型：
--
作者：
D. Berkov
本章致力于讨论在考虑热涨落的情况下对动态再磁化性质进行数值模拟所产生的一般问题。在简要介绍了微磁学中的耗散处理之后，我们接着对微磁运动方程中包含热涨落时出现的困难进行了详细的分析，将这个确定性的微分方程式转化为随机的微分方程式。特别注意热噪声关联，这可能是连续微磁问题离散化的结果。最后，我们简要回顾了用于研究高能势垒跃迁的数值方法，也就是在标准朗之万动力学由于计算时间过大而失效的情况下。
关键词：
微磁模拟；
消散；
吉尔伯特阻尼；
朗之万动力学；
随机微积分；
热噪声；
能源障碍；
涨落耗散定理；
离散化效应
This chapter is devoted to general problems arising as a result of numerical simulations of dynamical remagnetization properties taking into account thermal fluctuations. After a short introduction to the dissipation treatment in micromagnetics, we proceed with the detailed analysis of difficulties emerging when thermal fluctuations are included in the micromagnetic equation of motion, converting this deterministic differential equation into a stochastic one. Special attention is paid to thermal noise correlations, which can appear as a consequence of the discretization of a continuous micromagnetic problem. We conclude with a brief review of numerical methods developed for the study of the transitions over high-energy barriers, that is, in the situation where standard Langevin dynamics fails due to prohibitively large computational times.
Keywords:
micromagnetic simulations;
dissipation;
Gilbert damping;
Langevin dynamics;
stochastic calculus;
thermal noise;
energy barriers;
fluctuation-dissipation theorem;
discretization effects