二维随机格点伊辛模型中相变的蒙特卡罗模拟  

Monte Carlo Simulation of Phase Transitions in a Two-Dimensional Random Lattice Ising Model

作　　者：刘洋 赵薇 周恒为 黄以能 Liu Yang;Zhao Wei;Zhou Hengwei;Huang Yineng(Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters,College of Physical Science and Technology,Yili Normal University,Yining,Xinjiang 835000,China)

机构地区：[1]伊犁师范大学物理科学与技术学院,新疆凝聚态相变与微结构实验室,新疆伊宁835000

出　　处：《伊犁师范大学学报（自然科学版）》2023年第2期25-31,共7页Journal of Yili Normal University：Natural Science Edition

基　　金：新疆维吾尔自治区重点实验室开放课题(2021D04015);伊犁师范大学研究生科研创新项目(YS2022G016)。

摘　　要：针对二维随机格点伊辛模型(2D-RSIM)至今仍未获得体系热平衡态的精确解,以及已有的蒙特卡罗(MC)模拟结果存在自旋空位的浓度?点不够多、系统性不够足等问题,采用MC方法,对模型体系的比热C随温度T变化,特别是所表现的相变行为随?的演化,进行了细致的MC模拟.结果表明,对所有的?值,C随着T变化存在一个峰,并且随着?变大,峰形由尖锐变得圆滑,说明2D-RSIM中发生了弥散相变,并且相变温度Tc随?的增大总体上单调降低,细致分析首次发现存在3个Tc随?线性变化的区域(Ⅰ区、Ⅱ区、Ⅲ区),其中Ⅰ区下降斜率最大,Ⅲ区下降斜率最小.In view of the fact that the two-dimensional random lattice Ising model(2D-RSIM) has not yet obtained an accurate solution to the thermal equilibrium state of the system,and the existing Monte Carlo(MC) simulation results have problems such as the concentration ? points of spin vacancy being not sufficient and systematical,this paper uses the MC method to conduct a detailed MC simulation of the specific heat C of the model system as a function of temperature T,especially the evolution of the phase transition behavior as a function of ?.The results show that for all ? values,C has a peak as T changes,and as ? increases,the peak shape changes from sharp to smooth,indicating that a diffuse phase transition occurs in 2D-RSIM,and the phase transition temperature Tcdecreases monotonously as ? increases.Detailed analysis has found for the first time that there are three regions(regions Ⅰ,Ⅱ,and Ⅲ) where Tclinearly changes with ?,with the largest decline slope in region Ⅰ and the smallest decline in region Ⅲ.

关 键 词：随机格点伊辛模型 相变 蒙特卡罗模拟 

分 类 号：O414[理学—理论物理]