AI 中文总结
研究莫尔菱形石墨烯中FCI到广义反常霍尔晶体转变原因，通过介观mRG反点器件准粒子充电及体电阻测量，排除边缘态平衡情况，支持相变观点，确立介观探针方法并为探测分数激发提供基础。
AI 中文摘要
莫尔材料为探索分数陈绝缘体（FCI）的物理性质提供了一个通用平台。最近在莫尔菱形石墨烯（mRG）中观察到，随着电子温度降低，从FCI演变为扩展的量子反常霍尔背景，这引发了一个基本问题：这是由于FCI边缘态未能达到平衡，还是由于体相中从FCI到广义反常霍尔晶体的真正相变？本文通过探测介观mRG反点器件中的准粒子充电和体电阻测量来解决这个问题，这两种方法对体相敏感且不受边缘态复杂性的影响。对mRG反点的隧穿揭示了在低温下填充因子ν = 1和2/3时，两种陈数态的准粒子都携带一个电子电荷。在ν = 2/3附近对体电阻的温度依赖性测量进一步表明，在低于约150mK的温度下，从FCI到广义反常霍尔晶体存在热力学相变。结果清楚地排除了边缘态平衡的情况，支持相变的情况。我们的工作确立了介观探针作为揭示莫尔材料中竞争基态的有力方法，并为探测FCI中的分数激发提供了基础。
英文摘要
Moiré materials realize a versatile platform for exploring the physics of fractional Chern insulators (FCIs). The recently observed evolution from FCIs to an extended quantum anomalous Hall background upon lowering the electronic temperature in moiré rhombohedral graphene (mRG)8 raises a fundamental question: Is it caused by a failure to equilibrate the edge states of an FCI or by a genuine phase transition in the bulk from an FCI to a generalized anomalous Hall crystal? Here we address this question by probing quasiparticle charging in a mesoscopic mRG antidot device and by bulk resistance measurements, both of which are bulk-sensitive and free from complications from edge states. Tunneling to the mRG antidot reveals quasiparticles carrying one electron charge for both Chern states at filling factors ν=1 and 2/3 at low temperatures. Temperature dependence measurements of the bulk resistance near ν=2/3 further suggest a thermodynamic phase transition from an FCI to a generalized anomalous Hall crystal at temperatures below about 150mK. The results clearly exclude the edge state equilibration scenario and favor the phase transition scenario. Our work establishes mesoscopic probes as a powerful approach to uncover competing ground states in moiré materials and provides a basis for probing fractionalized excitations in FCIs.
