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arXiv 2603.04515cond-mat.mes-hallcond-mat.quant-gascond-mat.stat-mechcond-mat.str-el
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有限 Su-Schrieffer-Heeger 链的热力学相变:亚稳态与热容量异常

Heat Capacity Anomalies and Thermal Crossovers in Finite Su-Schrieffer-Heeger Chains

Universidade Federal Fluminense(弗鲁米嫩塞联邦大学);Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México(墨西哥国立自治大学核科学研究所);Faculty of Electric Engineering, Universidad Michoacana de San Nicolás de Hidalgo(圣尼古拉斯德伊达尔戈米却肯自治大学电气工程学院);Centro de Ciencias Exactas, Universidad del Bío-Bío(比奥比奥大学精确科学中心);Departamento de Ciencias Básicas de la Facultad de Ciencias, Universidad del Bío-Bío(比奥比奥大学理学院基础科学系)

Carlos Magno da Conceição, Julio César Pérez-Pedraza, Alfredo Raya, Cristian Villavicencio

AI总结:

研究有限 SSH 链的热力学相变,揭示亚稳态与热容量异常,探讨拓扑、有限尺寸效应及热涨落的相互作用。

摘要:

我们研究了在热平衡状态下,固定温度和化学势下有限的 Su-Schrieffer-Heeger(SSH)链的热力学性质。利用微正则和广义微正则 ensemble,我们计算了温度、化学势和跃迁不对称性作为函数的能量密度、粒子数密度、熵和热容量。我们的分析揭示了非双极化配置中热容量出现局部最小值的亚稳态热力学相的出现,表明了一种不同于拓扑相变的二级相变。这种亚稳态相随着跃迁不对称性的增加和链长的增长而更加显著。我们证明,尽管拓扑性质由边界态决定,但本体热力学行为表现出丰富的相结构,可通过跃迁参数比来调节。这些发现为理解一维拓扑系统中拓扑、有限尺寸效应和热涨落之间的相互作用提供了见解,对冷原子、光子系统和拓扑电路等实验实现具有潜在意义。

英文摘要:

We investigate the thermodynamic properties of finite Su-Schrieffer-Heeger (SSH) chains in thermal equilibrium at fixed temperature and chemical potential. Using the canonical and grand canonical ensembles, we calculate the energy density, particle number density, entropy, and heat capacity as functions of temperature, chemical potential, and hopping asymmetry. Our analysis reveals a double-peak anomaly in the heat capacity for non-dimerized configurations, in which two maxima are separated by a local minimum. We identify this feature as a Schottky-type thermal crossover governed by two distinct energy scales. The anomaly is most pronounced when the chemical potential is comparable to the band scale, and its two maxima separate further as the hopping asymmetry increases and the chain length grows, reflecting the widening gap between the two energy scales and the increasing density of states. We demonstrate that while the topological properties are determined by boundary states, the bulk thermodynamic behavior exhibits a rich crossover structure that can be tuned through the hopping parameter ratio. These findings provide insights into the interplay between topology, finite-size effects, and thermal fluctuations in one-dimensional topological systems, with potential implications for experimental realizations in cold atoms, photonic systems, and topoelectrical circuits.

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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