Topological Order Without Band Topology in Moiré Graphene

Fuente: arXiv
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Main Authors: Liu, Hui, Perea-Causin, Raul, Liu, Zhao, Bergholtz, Emil J.
Format: Preprint
Published: 2025
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_version_ 1866912653633388544
author Liu, Hui
Perea-Causin, Raul
Liu, Zhao
Bergholtz, Emil J.
author_facet Liu, Hui
Perea-Causin, Raul
Liu, Zhao
Bergholtz, Emil J.
contents The discovery of zero-field fractional Chern insulators (FCIs) in moiré materials has attracted intense interest in the interplay between topology and correlations. Here, we demonstrate that fractionalized topological order can emerge under realistic conditions even within a topologically trivial moiré band. By projecting long-range Coulomb interactions into a trivial band of twisted multilayer graphene, we identify a set of incompressible FCI ground states exhibiting fractional quantized Hall conductance. Their Laughlin-like behavior is further confirmed through the particle-cut entanglement spectrum. We trace the origin of this phase to the strongly inhomogeneous distribution of quantum geometry within the moiré Brillouin zone, which reshapes interaction effects independently of the band topology. Extending this heuristic quantum geometric mechanism, we demonstrate that similarly unexpected Laughlin-like FCIs can also be stabilized in higher-Chern-number moiré bands under experimentally accessible conditions. Our results establish realistic scenarios under which many-body topological order can emerge independently of single-particle band topology.
format Preprint
id arxiv_https___arxiv_org_abs_2510_15027
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Topological Order Without Band Topology in Moiré Graphene
Liu, Hui
Perea-Causin, Raul
Liu, Zhao
Bergholtz, Emil J.
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The discovery of zero-field fractional Chern insulators (FCIs) in moiré materials has attracted intense interest in the interplay between topology and correlations. Here, we demonstrate that fractionalized topological order can emerge under realistic conditions even within a topologically trivial moiré band. By projecting long-range Coulomb interactions into a trivial band of twisted multilayer graphene, we identify a set of incompressible FCI ground states exhibiting fractional quantized Hall conductance. Their Laughlin-like behavior is further confirmed through the particle-cut entanglement spectrum. We trace the origin of this phase to the strongly inhomogeneous distribution of quantum geometry within the moiré Brillouin zone, which reshapes interaction effects independently of the band topology. Extending this heuristic quantum geometric mechanism, we demonstrate that similarly unexpected Laughlin-like FCIs can also be stabilized in higher-Chern-number moiré bands under experimentally accessible conditions. Our results establish realistic scenarios under which many-body topological order can emerge independently of single-particle band topology.
title Topological Order Without Band Topology in Moiré Graphene
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2510.15027