Magic in twisted transition metal dichalcogenide bilayers

Abstract

The long wavelength moiré superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moiré bands in twisted transition metal dichalcogenide homobilayers, focusing on WSe${}_2$, at small twist angles using a combination of first principles density functional theory, continuum modeling, and Hartree-Fock approximation. We reveal the rich physics at small twist angles $\theta <4^{\circ }$, and identify a particular magic angle at which the top valence moiré band achieves almost perfect flatness. In the vicinity of this magic angle, we predict the realization of a generalized Kane-Mele model with a topological flat band, interaction-driven Haldane insulator, and Mott insulators at the filling of one hole per moiré unit cell. The combination of flat dispersion and uniformity of Berry curvature near the magic angle holds promise for realizing fractional quantum anomalous Hall effect at fractional filling. We also identify twist angles favorable for quantum spin Hall insulators and interaction-induced quantum anomalous Hall insulators at other integer fillings.

References in corpus (8)

• Computational 2D Materials Database: Electronic Structure of Transition-Metal Dichalcogenides and Oxides
• Quantum anomalous Hall effect from intertwined moiré bands
• Bulk Topological Invariants in Noninteracting Point Group Symmetric Insulators
• Hartree-Fock study of the moiré Hubbard model for twisted bilayer transition metal dichalcogenides
• Multifaceted moiré superlattice physics in twisted WSe${}_2$ bilayers
• Theory of tunable flux lattices in the homobilayer moiré of twisted and uniformly strained transition metal dichalcogenides
• Spin-valley density wave in moiré materials
• Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

Cited by in corpus (41)

• Quantum anomalous Hall effect from intertwined moiré bands
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• Transferable E(3) equivariant parameterization for Hamiltonian of molecules and solids
• 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
• Pair-density-wave and chiral superconductivity in twisted bilayer transition-metal-dichalcogenides
• When Superconductivity Crosses Over: From BCS to BEC
• Chiral Kondo Lattice in Doped MoTe${}_2$/WSe${}_2$ Bilayers
• Dynamical Mean Field Theory of Moiré Bilayer Transition Metal Dichalcogenides: Phase Diagram, Resistivity, and Quantum Criticality
• Intercell Moiré Exciton Complexes in Electron Lattices
• Competing magnetic states in transition metal dichalcogenide moiré materials
• Observation of flat $\Gamma$ moiré bands in twisted bilayer WSe${}_2$
• Spin-triplet superconductivity from interband effect in doped insulators
• Giant proximity exchange and flat Chern band in 2D magnet-semiconductor heterostructures
• Recent Developments in Fractional Chern Insulators
• 1/4 is the new 1/2 when topology is intertwined with Mottness
• Intrinsic spin Hall torque in a moire Chern magnet
• Moiré induced topology and flat bands in twisted bilayer WSe${}_2$: A first-principles study
• Nematic excitonic insulator in transition metal dichalcogenide moiré heterobilayers
• Emergent flat band and topological Kondo semimetal driven by orbital-selective correlations
• Chiral valley phonons and flat phonon bands in moiré materials
• Multilayer graphene with a superlattice potential
• Pair density wave and loop current promoted by van Hove singularities in moiré systems
• Disorder induced 2D metal-insulator transition in moiré transition metal dichalcogenide multilayers
• Nematic, chiral and topological superconductivity in transition metal dichalcogenides
• Staggered Pseudo Magnetic Field in Twisted Transition Metal Dichalcogenides: Physical Origin and Experimental Consequences
• Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides
• Magic-angle Twisted Bilayer Systems with Quadratic-Band-Touching: Exactly Flat Bands with High-Chern Number
• Twisted-bilayer FeSe and the Fe-based superlattices
• Switching between Mott-Hubbard and Hund physics in moiré quantum simulators
• Pseudogap metal and magnetization plateau from doping moiré Mott insulator
• Universality of moiré physics in collapsed chiral carbon nanotubes
• Double and Quadruple Flat Bands tuned by Alternative magnetic Fluxes in Twisted Bilayer Graphene
• Dissipation Induced Flat Bands
• Symmetric Wannier states and tight-binding model for quantum spin Hall bands in AB-stacked MoTe${}_2$/WSe${}_2$
• Pomeranchuk Effect and Tunable Quantum Phase Transitions in 3L-MoTe2/WSe2
• Ultrafast control of moiré pseudo-electromagnetic field in homobilayer semiconductors
• Engineering chiral topological superconductivity in twisted Ising superconductors
• Tunable superconductivity coexisting with the anomalous Hall effect in 1T'-WS2