Hofstadter states and reentrant charge order in a semiconductor moiré lattice

Fuente: arXiv
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Main Authors: Kometter, Carlos R., Yu, Jiachen, Devakul, Trithep, Reddy, Aidan P., Zhang, Yang, Foutty, Benjamin A., Watanabe, Kenji, Taniguchi, Takashi, Fu, Liang, Feldman, Benjamin E.
Format: Preprint
Published: 2022
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author Kometter, Carlos R.
Yu, Jiachen
Devakul, Trithep
Reddy, Aidan P.
Zhang, Yang
Foutty, Benjamin A.
Watanabe, Kenji
Taniguchi, Takashi
Fu, Liang
Feldman, Benjamin E.
author_facet Kometter, Carlos R.
Yu, Jiachen
Devakul, Trithep
Reddy, Aidan P.
Zhang, Yang
Foutty, Benjamin A.
Watanabe, Kenji
Taniguchi, Takashi
Fu, Liang
Feldman, Benjamin E.
contents The emergence of moiré materials with flat bands provides a platform to systematically investigate and precisely control correlated electronic phases. Here, we report local electronic compressibility measurements of a twisted WSe$_2$/MoSe$_2$ heterobilayer which reveal a rich phase diagram of interpenetrating Hofstadter states and electron solids. We show that this reflects the presence of both flat and dispersive moiré bands whose relative energies, and therefore occupations, are tuned by density and magnetic field. At low densities, competition between moiré bands leads to a transition from commensurate arrangements of singlets at doubly occupied sites to triplet configurations at high fields. Hofstadter states (i.e., Chern insulators) are generally favored at high densities as dispersive bands are populated, but are suppressed by an intervening region of reentrant charge-ordered states in which holes originating from multiple bands cooperatively crystallize. Our results reveal the key microscopic ingredients that favor distinct correlated ground states in semiconductor moiré systems, and they demonstrate an emergent lattice model system in which both interactions and band dispersion can be experimentally controlled.
format Preprint
id arxiv_https___arxiv_org_abs_2212_05068
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Hofstadter states and reentrant charge order in a semiconductor moiré lattice
Kometter, Carlos R.
Yu, Jiachen
Devakul, Trithep
Reddy, Aidan P.
Zhang, Yang
Foutty, Benjamin A.
Watanabe, Kenji
Taniguchi, Takashi
Fu, Liang
Feldman, Benjamin E.
Mesoscale and Nanoscale Physics
The emergence of moiré materials with flat bands provides a platform to systematically investigate and precisely control correlated electronic phases. Here, we report local electronic compressibility measurements of a twisted WSe$_2$/MoSe$_2$ heterobilayer which reveal a rich phase diagram of interpenetrating Hofstadter states and electron solids. We show that this reflects the presence of both flat and dispersive moiré bands whose relative energies, and therefore occupations, are tuned by density and magnetic field. At low densities, competition between moiré bands leads to a transition from commensurate arrangements of singlets at doubly occupied sites to triplet configurations at high fields. Hofstadter states (i.e., Chern insulators) are generally favored at high densities as dispersive bands are populated, but are suppressed by an intervening region of reentrant charge-ordered states in which holes originating from multiple bands cooperatively crystallize. Our results reveal the key microscopic ingredients that favor distinct correlated ground states in semiconductor moiré systems, and they demonstrate an emergent lattice model system in which both interactions and band dispersion can be experimentally controlled.
title Hofstadter states and reentrant charge order in a semiconductor moiré lattice
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2212.05068