Gate-tunable flat bands in van der Waals patterned dielectric superlattices

Abstract

Superlattice engineering provides the means to reshape the fabric felt by quasiparticles moving in a material. Here we argue that bandstructure engineering with superlattices can be pushed to the extreme limit by stacking gapped van der Waals (vdW) materials on patterned dielectric substrates. Specifically, we find that high quality vdW patterned dielectric superlattices (PDS) realize a series of robust flat bands that can be directly switched on and off by gate voltage in situ. In contrast to existing superlattice platforms, these flat bands are realized without the need for fine tuning. Instead, the bands become flat as the gate voltage increases in magnitude. The characteristics of PDS flatbands are highly tunable: the type of flatband (single non-degenerate or dirac-cone-like), localization length, and interaction energy are sensitive to the applied gate voltage. As a result, electron-electron interactions in the PDS flatbands can become stronger than both the bandwidth and disorder broadening, providing a setting for correlated behavior such as flatband ferromagnetism. We expect PDS flatbands can be experimentally realized in a range of readily available gapped vdW materials such as monolayer transition metal dichalcogenides, e.g. WSe2.

References in corpus (31)

• Van der Waals heterostructures
• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• 2D materials and van der Waals heterostructures
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Moire bands in twisted double-layer graphene
• Hofstadter's butterfly in moire superlattices: A fractal quantum Hall effect
• Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure
• Graphene bilayer with a twist: electronic structure
• Moiré Excitons in Van der Waals Heterostructures
• Cloning of Dirac fermions in graphene superlattices
• A self-consistent theory for graphene transport
• Signatures of moiré-trapped valley excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
• Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Quantum Hall Ferromagnetism in Graphene
• Topological insulators in twisted transition metal dichalcogenide homobilayers
• Hubbard model physics in transition metal dichalcogenide moiré bands
• Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
• Strain Solitons and Topological Defects in Bilayer Graphene
• Evidence of Gate-Tunable Mott Insulator in Trilayer Graphene-Boron Nitride Moiré Superlattice
• Electrically switchable Berry curvature dipole in the monolayer topological insulator WTe2
• Topological mosaic in Moiré superlattices of van der Waals heterobilayers
• Band Structure Engineering of 2D Materials using Patterned Dielectric Superlattices
• Topological Bloch Bands in Graphene Superlattices
• Electron quantum metamaterials in van der Waals heterostructures
• Symmetry, spin-texture, and tunable quantum geometry in a WTe${}_2$ monolayer
• Coulomb disorder in three-dimensional Dirac systems
• Magnetic Proximity Effect in a van der Waals Moiré Superlattice
• Theory of the random potential and conductivity at the surface of a topological insulator

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• Multilayer graphene with a superlattice potential
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• Designer Meron Lattice on the Surface of a Topological Insulator
• Quantum transport in flat bands and super-metallicity
• Chiral model of twisted bilayer graphene realized in a monolayer
• Lattice reconstruction in MoSe${}_2$-WSe${}_2$ heterobilayers synthesized by chemical vapor deposition
• Designing topology and fractionalization in narrow gap semiconductor films via electrostatic engineering
• ${\mathbb{Z}}_2$-Nontrivial Moiré Minibands and Interaction-Driven Quantum Anomalous Hall Insulators in Topological Insulator Based Moiré Heterostructures
• Topological phases in N-layer ABC-graphene boron-nitride moire superlattices
• Criteria for deterministic single-photon emission in two-dimensional atomic crystals
• Designing Band Structures by Patterned Dielectric Superlattices
• Understanding Disorder in Monolayer Graphene Devices with Gate-Defined Superlattices
• Quantum-geometric dipole: a topological boost to flavor ferromagnetism in flat bands
• Giant Shift Current in Electrically-Tunable Superlattice Bilayer Graphene
• Efficient prediction of topological superlattice bands with spin-orbit coupling
• Quantum simulator of extended bipartite Hubbard model with broken sublattice symmetry: magnetism, correlations, and phase transitions
• Freeform nanostructuring of hexagonal boron nitride
• Theory of engineering flat bands in graphene using doubly-periodic electrostatic gating
• Designing Flat Bands and Pseudo-Landau Levels in GaAs with Patterned Gates