熵驱动的扩展整数与分数量子霍尔体系之间的转变
Entropy-driven transitions between extended integer and fractional quantum Hall regimes
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中文总结 AI 辅助
本文研究扩展整数与分数量子霍尔态间的热转变，提出戈德斯通模或软有隙模的熵驱动机制，并在莫尔菱方石墨烯中通过软磁旋子解释实验观测到的热演化现象。
中文摘要 AI 辅助
具有共存维格纳晶体序的电子态有时可以在一定的电子密度范围内表现出量子霍尔效应，即在没有无序的情况下表现出“扩展”的量子霍尔（QH）平台。这种扩展的量子霍尔态随后可以在相同的密度范围内与其他量子霍尔态竞争，从而允许它们之间发生一级热转变。在这里，我们分析了若干设置，其中与戈德斯通模（例如，磁振子或声子）或软有隙模（例如，磁旋子）相关的熵驱动了竞争性量子霍尔体系之间的有限温度转变。将该框架应用于莫尔菱方石墨烯，我们认为分数量子反常霍尔态中的软磁旋子为观察到的从扩展整数量子霍尔到分数量子霍尔体系的热演化提供了一种合理的体机制。
英文摘要
Electronic states with coexisting Wigner-crystal order can sometimes exhibit a quantum Hall effect over a finite range of electron densities---i.e., exhibit ``extended'' quantum Hall (QH) plateaus in the absence of disorder. Such an extended quantum Hall state can then compete with other QH states over the same density range, allowing a first-order thermal transition between them. Here, we analyze several settings in which the entropy associated with Goldstone modes (e.g., magnons or phonons) or soft gapped modes (e.g., magnetoroton) drives a finite-temperature transition between competing QH regimes. Applying this framework to moiré rhombohedral graphene, we argue that a soft magnetoroton in a fractional quantum anomalous Hall state provides a plausible bulk mechanism for the observed thermal evolution from an extended integer QH to a fractional QH regime.
发表机构
- University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）
- Stanford University（斯坦福大学）
机构由 AI 辅助整理，请以论文原文为准。
