Thermal reversal of magnetization as "random walk" dynamics of a nonlinear oscillator

被引:13
作者
Safonov, VL [1 ]
机构
[1] Univ Calif San Diego, Ctr Magnet Recording Res, La Jolla, CA 92093 USA
关键词
D O I
10.1063/1.369787
中图分类号
O59 [应用物理学];
学科分类号
摘要
Coherent rotation of magnetization in a grain is represented as the dynamics of a nonlinear oscillator excited by random force. A stochastic differential equation is introduced to study the role of thermal fluctuations and the corresponding Fokker-Planck equation is obtained. It is shown that conventional Landau-Lifshitz-Gilbert damping is consistent with thermodynamics only for small deviations of the magnetization from the equilibrium state. An exact formula for the first passage time from the initial potential well is obtained. (C) 1999 American Institute of Physics. [S0021-8979(99)36808-0].
引用
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页码:4370 / 4372
页数:3
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