Thermal crossover from a Chern insulator to a fractional Chern insulator in pentalayer graphene

Abstract

By theoretically analyzing the recent temperature dependent transport data in pentalayer graphene [Lu et al., arXiv:2408.10203], we establish that the experimentally observed transition from low-temperature quantum anomalous Hall effect to higher-temperature fractional quantum anomalous Hall effect is a crossover phenomenon arising from the competition between interaction and disorder energy scales, with the likely zero temperature ground state of the system being either a localized insulator or a Chern insulator with a quantized anomalous Hall effect. In particular, the intriguing suppression of FQAHE in favor of QAHE with decreasing temperature is explained as arising from the low-temperature localization of the carriers where disorder overcomes the interaction effects. We provide a detailed analysis of the data in support of the crossover scenario.

Published version

References in corpus (8)

• Theory of fractional Chern insulator states in pentalayer graphene moiré superlattice
• Quantum anomalous Hall crystal at fractional filling of moiré superlattices
• Quantum phases of disordered flatband lattice fractional quantum Hall systems
• Fractional Quantum Hall State at Filling Factor $\nu =1/4$ in Ultra-High-Quality GaAs 2D Hole Systems
• Integer and fractional quantum anomalous Hall effects in pentalayer graphene
• Electronic transport, metal-insulator transition, and Wigner crystallization in transition metal dichalcogenide monolayers
• Correlated states of 2D electrons near the Landau level filling $\nu =1/7$
• Thermal melting of a quantum electron solid in the presence of strong disorder: Anderson versus Wigner

Cited by in corpus (9)

• Extended quantum anomalous Hall effect in moiré structures: phase transitions and transport
• Impurity-induced thermal crossover in fractional Chern insulators
• Edge-driven transition between extended quantum anomalous Hall crystal and fractional Chern insulator in rhombohedral graphene multilayers
• Entropy-Enhanced Fractional Quantum Anomalous Hall Effect
• Generic integer and fractional quantum anomalous Hall crystals from interaction-driven band folding
• Interplay of superconducting, metallic, and crystalline states of composite fermions at $\nu =1/6$ in wide quantum wells
• Chern-Selective multi-valley Flat Bands in Twisted Mono-Bilayer and Mono-Trilayer MoTe${}_2$
• Elastic Response and Instabilities of Anomalous Hall Crystals
• Various electronic crystal phases in rhombohedral graphene multilayers