Hofstadter states and reentrant charge order in a semiconductor moiré lattice

Abstract

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.

References in corpus (5)

• Moiré heterostructures as a condensed matter quantum simulator
• Metal-insulator transition in two-dimensional electron systems
• Gate-tunable heavy fermions in a moiré Kondo lattice
• Direct STM Measurements of R- and H-type Twisted MoSe2/WSe2 Heterostructures
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Cited by in corpus (11)

• A Microscopic Perspective on Moiré Materials
• Mapping twist-tuned multiband topology in bilayer WSe${}_2$
• Spectroscopy of the Fractal Hofstadter Energy Spectrum
• Hofstadter spectrum of Chern bands in twisted transition metal dichalcogenides
• Inhomogeneous high temperature melting and decoupling of charge density waves in spin-triplet superconductor UTe2
• High spatial resolution charge sensing of quantum Hall states
• Helical trilayer graphene in magnetic field: Chern mosaic and higher Chern number ideal flat bands
• Particle-hole asymmetric ferromagnetism and spin textures in the triangular Hubbard-Hofstadter model
• Orbital Magnetic Field Driven Metal-Insulator Transition in Strongly Correlated Electron Systems
• Magnetic Hofstadter cascade in a twisted semiconductor homobilayer
• Anomalous Landau level gaps near magnetic transitions in monolayer WSe${}_2$