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arXiv 1305.7108cond-mat.stat-mech
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随机场作用下二维动力学伊辛模型的响应

Response of Two-dimensional Kinetic Ising Model under Stochastic Field

Asim Ghosh, Bikas K. Chakrabarti

摘要:

本文用蒙特卡罗动力学方法研究了二维动力学伊辛模型在二元($\pm h_0$)随机场$h(t)$作用下的时间($t$)依赖的单自旋平均磁化强度($m(t)$)行为.随机场的时间依赖性使得其在每个连续时间间隔$τ$上的平均值被确保为零(没有任何波动)。平均磁化强度$Q=(1/τ)\int_{0}^τ m(t) dt$被认为是系统的序参量。得到了($h_0,τ$)平面内的相图。研究了序参量的涨落及其跨相边界的标度性质。这些研究表明,过渡的性质是伊辛(静态伊辛普适类)的磁场振幅$h_0$低于一些阈值$h_0^c(τ)$(依赖于$τ$值; $h_0^c\rightarrow0$作为$τ\rightarrow\infty$跨越相位边界)。在这些$h_0^c (τ)$之外,过渡不再是连续的。

英文摘要:

We study, using Monte Carlo dynamics, the time ($t$) dependent average magnetization per spin $m(t)$ behavior of 2-D kinetic Ising model under a binary ($\pm h_0$) stochastic field $h(t)$. The time dependence of the stochastic field is such that its average over each successive time interval $τ$ is assured to be zero (without any fluctuation). The average magnetization $Q=(1/τ)\int_{0}^τ m(t) dt$ is considered as order parameter of the system. The phase diagram in ($h_0,τ$) plane is obtained. Fluctuations in order parameter and their scaling properties are studied across the phase boundary. These studies indicate that the nature of the transition is Ising like (static Ising universality class) for field amplitudes $h_0$ below some threshold value $h_0^c(τ)$ (dependent on $τ$ values; $h_0^c\rightarrow0$ as $τ\rightarrow\infty$ across the phase boundary) . Beyond these $h_0^c (τ)$, the transition is no longer continuous.

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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