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arXiv 1010.4437cond-mat.stat-mech
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热力学相变的驻点方法

Stationary points approach to thermodynamic phase transitions

Michael Kastner

摘要:

采用基于势能驻点的方法研究了热力学函数的非解析性。对于有限系统,每个驻点被发现导致非解析的微正则熵,并明确推导出这个非解析项的函数形式。随着系统规模的增加,非解析项的阶数增加,导致熵的可微性增加。据发现,只有“渐近平坦”的固定点可能会导致nonanalyticity,生存在热力学极限,这个属性是用来推导一个分析标准建立存在或不存在的相变。我们简述了如何利用这一结果来解析计算经典自旋模型的跃迁能。

英文摘要:

Nonanalyticities of thermodynamic functions are studied by adopting an approach based on stationary points of the potential energy. For finite systems, each stationary point is found to cause a nonanalyticity in the microcanonical entropy, and the functional form of this nonanalytic term is derived explicitly. With increasing system size, the order of the nonanalytic term grows, leading to an increasing differentiability of the entropy. It is found that only "asymptotically flat" stationary points may cause a nonanalyticity that survives in the thermodynamic limit, and this property is used to derive an analytic criterion establishing the existence or absence of phase transitions. We sketch how this result can be employed to analytically compute transition energies of classical spin models.

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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