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arXiv 0911.3748cond-mat.stat-mech
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亚稳型动力学相变阈值点附近弛豫时间的渐近形式和标度性质

Asymptotic forms and scaling properties of the relaxation time near threshold points in spinodal-type dynamical phase transitions

Takashi Mori, Seiji Miyashita, Per Arne Rikvold

摘要:

我们研究了外场变化下双光子态之间转换过程中阈值点处弛豫时间的临界性质。特别地,我们通过分析相应的Fokker-Planck方程的标度性质,研究了无限长程相互作用模型(Husimi-Temperley模型)的旋节点附近的弛豫过程。我们还确认了原始主方程的直接数值解,并通过动力学蒙特卡罗模拟的随机衰变过程中得到的标度关系。特别地,我们研究了弛豫时间在旋节点附近发散的渐近形式,并重新检验了它的标度性质。我们进一步扩展分析瞬态临界现象,如阈值行为下的一般外部驱动扰动发散开关时间。这模拟了自旋交叉材料中的光激发过程。在纳米尺寸制造的持续发展中,开关过程的这种尺寸依赖性应该是一个重要的问题,并且这里获得的性质将适用于广泛的物理过程。

英文摘要:

We study critical properties of the relaxation time at a threshold point in switching processes between bistable states under change of external fields. In particular, we investigate the relaxation processes near the spinodal point of the infinitely long-range interaction model (the Husimi-Temperley model) by analyzing the scaling properties of the corresponding Fokker-Planck equation. We also confirm the obtained scaling relations by direct numerical solution of the original master equation, and by kinetic Monte Carlo simulation of the stochastic decay process. In particular, we study the asymptotic forms of the divergence of the relaxation time near the spinodal point, and reexamine its scaling properties. We further extend the analysis to transient critical phenomena such as a threshold behavior with diverging switching time under a general external driving perturbation. This models photo-excitation processes in spin-crossover materials. In the ongoing development of nano-size fabrication, such size-dependence of switching processes should be an important issue, and the properties obtained here will be applicable to a wide range of physical processes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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