Composite Fermion Theory of Fractional Chern Insulators in Rhombohedral Graphene
Abstract
The experimental observation of the fractional quantum anomalous Hall effect in rhombohedral graphene multilayers has raised questions about the nature of the fractional Chern insulator (FCI) states and the role of the moiré potential. In this Letter we develop a composite fermion (CF) description and discuss how moiré modulation and Coulomb interactions stabilize the FCI ground states. Under a flux-attachment transformation and mean-field approximation, the CF spectrum forms Landau levels that are further split by the moiré potential. At moiré filling fractions in the Jain sequence, an integer number of CF bands are occupied, resulting in an incompressible ground state with fractionally quantized Hall response. Remarkably, when the attached flux opposes the Berry curvature of the conduction band of rhombohedral graphene, the CF Landau levels are widely spaced in energy and delocalized across layers, leading to a reduced density of states that helps protect the CF mean-field state and amplifying effects of the moiré potential acting on the layer away from the doped electrons. Interactions between CFs further enlarge the moiré-induced band gap and stabilize the FCI ground state. Our work sheds light on the nature of the FCI states in rhombohedral graphene and provides a new theoretical framework for further studies.
Related
- Quantum Phase Transitions and Fractional Quantized Anomalous Hall Insulators in Rhombohedral Graphene
- Transdimensional Chern insulators in rhombohedral multilayer graphene superlattices
- Spin-polarized Superconductivity and High-Chern Insulators in Twisted Rhombohedral Graphene Family
- Coexistence of Superconductivity and Chern insulators with |C| ≥ 1 in twisted rhombohedral bilayer-trilayer graphene
- Fractional Chern insulators and composite Fermi liquids vs. charge order in twisted MoTe2
BibTeX
@misc{ding2026composite,
title = {{Composite Fermion Theory of Fractional Chern Insulators in Rhombohedral Graphene}},
author = {Peize Ding and Andrew J. Millis and Yongxin Zeng},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07174},
eprint = {2610.07174},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07174},
}
RIS
TY - UNPB
TI - Composite Fermion Theory of Fractional Chern Insulators in Rhombohedral Graphene
AU - Peize Ding
AU - Andrew J. Millis
AU - Yongxin Zeng
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.07174
UR - https://arxiv.org/abs/2610.07174
AB - The experimental observation of the fractional quantum anomalous Hall effect in rhombohedral graphene multilayers has raised questions about the nature of the fractional Chern insulator (FCI) states and the role of the moiré potential. In this Letter we develop a composite fermion (CF) description and discuss how moiré modulation and Coulomb interactions stabilize the FCI ground states. Under a flux-attachment transformation and mean-field approximation, the CF spectrum forms Landau levels that are further split by the moiré potential. At moiré filling fractions in the Jain sequence, an integer number of CF bands are occupied, resulting in an incompressible ground state with fractionally quantized Hall response. Remarkably, when the attached flux opposes the Berry curvature of the conduction band of rhombohedral graphene, the CF Landau levels are widely spaced in energy and delocalized across layers, leading to a reduced density of states that helps protect the CF mean-field state and amplifying effects of the moiré potential acting on the layer away from the doped electrons. Interactions between CFs further enlarge the moiré-induced band gap and stabilize the FCI ground state. Our work sheds light on the nature of the FCI states in rhombohedral graphene and provides a new theoretical framework for further studies.
ER -