arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0812.1955cond-mat.stat-mech
收藏

用$ρ^6$模型计算三维类伊辛体系在外场中的自由能

Method of Calculating the Free Energy of Three-Dimensional Ising-Like System in an External Field with the Use of the $ρ^6$ Model

I. V. Pylyuk, M. P. Kozlovskii

备注：
LaTeX, 23 pages, 1 eps figure
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

在温度高于$T_c$的临界值（$T_c$是在没有外场的情况下的相变温度）的情况下，在更高的非高斯近似（$ρ^6$模型）中发展了计算三维类伊辛系统在均匀外场中的自由能的微观方法。通过分离考虑温度和场的序参量波动的短波和长波自旋密度振荡模式的贡献，发现系统的自由能。我们的分析计算不涉及标度变量的幂级数，并且在临界点附近的整个场-温度平面内有效，包括极限场$\tilde h_c$附近的区域，该极限场将外场分为弱场和强场（即，交叉区域）。在这个区域，温度和场对系统的影响是等效的，标度变量是单位的数量级，幂级数是无效的。所得到的表达式的自由能包含的主导条款和条款确定的温度和场汇流校正。

英文摘要：

The microscopic approach to calculating the free energy of a three-dimensional Ising-like system in a homogeneous external field is developed in the higher non-Gaussian approximation (the $ρ^6$ model) at temperatures above the critical value of $T_c$ ($T_c$ is the phase-transition temperature in the absence of an external field). The free energy of the system is found by separating the contributions from the short- and long-wave spin-density oscillation modes taking into account both the temperature and field fluctuations of the order parameter. Our analytical calculations do not involve power series in the scaling variable and are valid in the whole field-temperature plane near the critical point including the region in the vicinity of the limiting field $\tilde h_c$, which divides external fields into the weak and strong ones (i.e., the crossover region). In this region, the temperature and field effects on the system are equivalent, the scaling variable is of the order of unity, and power series are not efficient. The obtained expression for the free energy contains the leading terms and terms determining the temperature and field confluent corrections.

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。

↑