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arXiv 0910.3203cond-mat.stat-mechcond-mat.other
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带剪切的伊辛模型临界行为中相变的Monte Carlo研究

Monte Carlo study of the phase transition in the Critical behavior of the Ising model with shear

G. P. Saracco, G. Gonnella

摘要:

通过研究具有非守恒动力学和外部剪切剖面的伊辛模型在短时间内的动力学演化,分析了该模型的临界行为。从高温无序组态(FDC),临界温度$T_c$确定时的序参量,定义为横向自旋分布的绝对值,表现出幂律行为的指数是一个组合的一些临界指数的过渡。对于标记为$\dotγ$的剪切场幅度的每个值,已经估计了$T_c$,并且已经发现了两个阶段:1)在$\dotγ$的低值处的增长阶段,其中$T_c\sim\dotγ^ψ$和$ψ=0.52(3)$ ; 2)在大的$\dotγ$处的饱和状态。研究了所有自旋指向相同方向的基态组态(GSC)的动力学演化,发现$T_c(\dotγ)$的值相同。通过组合从每个初始构型获得的相应幂律的指数,计算临界指数集。这些值,在大的外场幅度,定义了一个新的临界行为不同于伊辛模型和其他驱动晶格气体。

英文摘要:

The critical behavior of the Ising model with non-conserved dynamics and an external shear profile is analyzed by studying its dynamical evolution in the short time regime. Starting from high temperature disordered configurations (FDC), the critical temperature $T_c$ is determined when the order parameter, defined as the absolute value of the transversal spin profile, exhibits a power-law behavior with an exponent that is a combination of some of the critical exponents of the transition. For each value of the shear field magnitude, labeled as $\dotγ$, $T_c$ has been estimated and two stages have been found: 1) a growing stage at low values of $\dotγ$, where $T_c\sim\dotγ^ψ$ and $ψ=0.52(3)$; 2) a saturation regime at large $\dotγ$. The same values of $T_c(\dotγ)$ were found studying the dynamical evolution from the ground state configuration (GSC) with all spins pointing in the same direction. By combining the exponents of the corresponding power laws obtained from each initial configuration the set of critical exponents was calculated. These values, at large external field magnitude, define a new critical behavior different from that of the Ising model and of other driven lattice gases.

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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