Excitonic Chern insulator and kinetic ferromagnetism in MoTe${}_2$/WSe${}_2$ moiré bilayer

Abstract

We propose a new mechanism for quantum anomalous Hall (QAH) effect in the AB stacked MoTe${}_2$/WSe${}_2$ system. Based on the observation that the inter-layer tunneling is suppressed in the AB stacking, we consider a model with two layers coupled through the Coulomb interaction. The moiré lattices of the two layers are shifted to form a honeycomb lattice together. Initially, the system is in a layer-polarized Mott insulator at ${\nu }_T=1$. But with a displacement field, an equal number of holes and electrons are doped into the two layers respectively and they form inter-layer exciton condensation. Through mean field theory, we find p$\pm$ip exciton condensation in a certain parameter regime, which leads to a Chern insulator with Chern number $C=\pm 1$. The valleys are polarized due to the kinetic energy instead of interaction. But the polarization in the two layers can be either the same or opposite depending on small perturbations away from a symmetric point. As a result, both valley polarized and inter-valley coherent (IVC) Chern insulator phases are possible. The latter has the same spin $S_z$ in the two layers.

arXiv comment5 pages, 3 figures

References in corpus (43)

• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Tuning superconductivity in twisted bilayer graphene
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Intrinsic quantized anomalous Hall effect in a moiré heterostructure
• Optical detection of Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices
• Magic continuum in twisted bilayer WSe2
• Tunable Correlated Chern Insulator and Ferromagnetism in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Electric Field Tunable Correlated States and Magnetic Phase Transitions in Twisted Bilayer-Bilayer Graphene
• Signatures of Gate-Tunable Superconductivity in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Spin-polarized Correlated Insulator and Superconductor in Twisted Double Bilayer Graphene
• Evidence of Gate-Tunable Mott Insulator in Trilayer Graphene-Boron Nitride Moiré Superlattice
• Quantum anomalous Hall effect from intertwined moiré bands
• Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene
• Correlated states in twisted double bilayer graphene
• Nearly Flat Chern Bands in Moiré Superlattices
• A mechanism for anomalous Hall ferromagnetism in twisted bilayer graphene
• Continuous Mott transition in semiconductor moiré superlattices
• Electrical switching of magnetic order in an orbital Chern insulator
• Quantum Criticality in Twisted Transition Metal Dichalcogenides
• Electrically tunable correlated and topological states in twisted monolayer-bilayer graphene
• Twisted Bilayer Graphene Aligned with Hexagonal Boron Nitride: Anomalous Hall Effect and a Lattice Model
• Ferromagnetism in narrow bands of moiré superlattices
• Theories for the correlated insulating states and quantum anomalous Hall phenomena in twisted bilayer graphene
• Collective Excitations of Quantum Anomalous Hall Ferromagnets in Twisted Bilayer Graphene
• Correlated interlayer exciton insulator in double layers of monolayer WSe2 and moiré WS2/WSe2
• Topological charge density waves at half-integer filling of a moiré superlattice
• Valley-Polarized Quantum Anomalous Hall State in Moiré MoTe${}_2$/WSe${}_2$ Heterobilayers
• Moiré Commensurability and the Quantum Anomalous Hall Effect in Twisted Bilayer Graphene on Hexagonal Boron Nitride
• SU(4) chiral spin liquid, exciton supersolid and electric detection in moiré bilayers
• Topological Phases in AB-Stacked MoTe${}_2$/WSe${}_2$: ${\mathbb{Z}}_2$ Topological Insulators, Chern Insulators, and Topological Charge Density Waves
• Quantum anomalous Hall effect from inverted charge transfer gap
• Spin-Orbit Coupling in Transition Metal Dichalcogenide Heterobilayer Flat Bands
• Anomalous Hall effect, magneto-optical properties, and nonlinear optical properties of twisted graphene systems
• Quantum Geometry and Stability of Moiré Flatband Ferromagnetism
• Ferromagnetism and its stability from the one-magnon spectrum in twisted bilayer graphene
• Quasiperiodicity, band topology, and moiré graphene
• Massive Dirac fermions in moiré superlattices: a route towards topological flat minibands
• Quantum anomalous Hall effect and electric-field-induced topological phase transition in AB-stacked MoTe${}_2$/WSe${}_2$ moiré heterobilayers
• Doping a Mott insulator with excitons in moiré bilayer: fractional superfluid, neutral Fermi surface and Mott transition
• Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

Cited by in corpus (16)

• Mapping twist-tuned multiband topology in bilayer WSe${}_2$
• Interaction-driven topological phase diagram of twisted bilayer MoTe${}_2$
• Chiral Kondo Lattice in Doped MoTe${}_2$/WSe${}_2$ Bilayers
• 1/4 is the new 1/2 when topology is intertwined with Mottness
• A New Era of Excitonic Insulators
• Polaron spectroscopy of a bilayer excitonic insulator
• Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides
• Topological Kondo semimetal and insulator in AB-stacked heterobilayer transition metal dichalcogenides
• Majorana zero modes in twisted transition metal dichalcogenides homobilayers
• Berry curvature, spin Hall effect and nonlinear optical response in moiré transition metal dichalcogenide heterobilayers
• Symmetric Wannier states and tight-binding model for quantum spin Hall bands in AB-stacked MoTe${}_2$/WSe${}_2$
• Correlated Topological Mixed-Valence Insulators in Moiré Hetero-Bilayers
• Topological $p_x+i{p}_y$ inter-valley coherent state in Moiré MoTe${}_2$/WSe${}_2$ heterobilayers
• Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
• Topological Kondo semimetals emulated in hetero-bilayer transition metal dichalcogenides
• Interplay between topology and electron-electron interactions in the moiré MoTe${}_2$/WSe${}_2$ heterobilayer