Abstract

A computer simulation of the phase transitions in a three-dimensional weakly diluted five-state Potts model on a simple cubic lattice is performed. Calculations are carried out for spin systems with periodic boundary conditions at spin concentrations of p = 1.0 and p = 0.90. Systems with linear dimensions L × L × L = N, L = 10–80 are considered. The temperature dependences of the specific heat, susceptibility, and magnetization as a function of the linear dimensions of the studied systems are obtained. Using the fourth-order Binder cumulants and using histogram-data analysis, it is shown that the presence of weak disorder in the form of nonmagnetic impurities of the order c = 10% (c = 1 – p, p is the spin concentration) does not affect the phase transition of the first-order.

中文翻译：

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三维弱稀释自旋系统中相变的计算机模拟

摘要

对简单立方晶格上的三维弱稀释五态 Potts 模型中的相变进行计算机模拟。在自旋浓度为p = 1.0 和p = 0.90时，对具有周期性边界条件的自旋系统进行计算。考虑线性尺寸L × L × L = N , L = 10–80 的系统。获得了作为所研究系统的线性尺寸函数的比热、磁化率和磁化强度的温度依赖性。使用四阶 Binder 累积量并使用直方图数据分析，表明存在以非磁性杂质形式存在的弱无序c = 10% ( c = 1 – p , p是自旋浓度) 不影响一阶的相变。