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arXiv 0709.1450cond-mat.dis-nncond-mat.stat-mech
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三维无序伊辛模型临界行为的计算机模拟

Computer simulation of the critical behavior of 3D disordered Ising model

V. Prudnikov, P. Prudnikov, A. Vakilov, A. Krinitsyn

摘要:

用蒙特卡罗方法研究了无序铁磁伊辛模型在大范围杂质原子浓度变化下的临界行为。测定了不同自旋浓度和不同线性尺寸样品的相关长度和磁化率随温度的变化关系。有限尺寸标度技术用于获得这些量的标度函数,其在临界区域中表现出普遍的行为;临界温度和静态临界指数也使用标度校正来确定。根据标度函数和临界指数随浓度变化的规律,得出了稀释伊辛模型存在两类具有不同特征的临界行为的结论,即弱和强无序系统存在两类不同的临界行为.

英文摘要:

The critical behavior of the disordered ferromagnetic Ising model is studied numerically by the Monte Carlo method in a wide range of variation of concentration of nonmagnetic impurity atoms. The temperature dependences of correlation length and magnetic susceptibility are determined for samples with various spin concentrations and various linear sizes. The finite-size scaling technique is used for obtaining scaling functions for these quantities, which exhibit a universal behavior in the critical region; the critical temperatures and static critical exponents are also determined using scaling corrections. On the basis of variation of the scaling functions and values of critical exponents upon a change in the concentration, the conclusion is drawn concerning the existence of two universal classes of the critical behavior of the diluted Ising model with different characteristics for weakly and strongly disordered systems.

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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