Entropy-driven transitions between extended integer and fractional quantum Hall regimes
Abstract
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.
Related
- Finite-size scaling theory of Rényi thermal entropy for second-order, first-order, and weakly first-order quantum phase transitions
- Field-driven quantum phase transitions in a spin-1/2 Heisenberg antiferromagnet on an extended Lieb lattice
- Successive Phase Transitions from a Composite Fermion Liquid to a Fractional Quantum Hall State at ν=3/2 Driven by In-Plane Magnetic Field
- Nonequilibrium Dynamical Quantum Phase Transitions in the Extended Agassi Model
- Quantum Phase Transitions and Fractional Quantized Anomalous Hall Insulators in Rhombohedral Graphene
BibTeX
@misc{kim2026entropydriven,
title = {{Entropy-driven transitions between extended integer and fractional quantum Hall regimes}},
author = {Kyung-Su Kim and Steven A. Kivelson},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.16483},
eprint = {2609.16483},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.16483},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Entropy-driven transitions between extended integer and fractional quantum Hall regimes
AU - Kyung-Su Kim
AU - Steven A. Kivelson
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.16483
UR - https://arxiv.org/abs/2609.16483
AB - 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.
ER -