Quantum-spin-Hall insulator with a large gap: single-layer 1T' WSe${}_2$

Abstract

Two-dimensional (2D) topological insulators (TIs) are promising platforms for low-dissipation spintronic devices based on the quantum spin Hall (QSH) effect, but experimental realization of such systems with a large band gap suitable for room-temperature applications has proven difficult. Here, we report the successful growth on bilayer graphene of a quasi-freestanding WSe${}_2$ single layer with the 1T' structure that does not exist in the bulk form of WSe${}_2$. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we observed a gap of 129 meV in the 1T' layer and an in-gap edge state located near the layer boundary. The system's 2D TI characters are confirmed by first-principles calculations. The observed gap diminishes with doping by Rb adsorption, ultimately leading to an insulator-semimetal transition. The discovery of this large-gap 2D TI with a tunable band gap opens up opportunities for developing advanced nanoscale systems and quantum devices.

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Cited by in corpus (46)

• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Coexistence of Intrinsic Superconductivity and Topological Insulator State in Monoclinic Phase WS2
• Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T'-WTe2
• Nanomaterials for Quantum Information Science and Engineering
• Atomically Thin Quantum Spin Hall Insulators
• Signature of large-gap quantum spin Hall state in the layered mineral jacutingaite
• Realization of AlSb in the double layer honeycomb structure: a robust new class of two-dimensional material
• The influence of lattice termination on the edge states of the quantum spin Hall insulator monolayer $1T^{\prime }$-WTe${}_2$
• Detection of second-order topological superconductors by Josephson junctions
• Design and realization of topological Dirac fermions on a triangular lattice
• Stanene: A Good Platform for Topological Insulator and Topological Superconductor
• Nonconventional screening of Coulomb interaction in two-dimensional semiconductors and metals: A comprehensive cRPA study of MX2 (M=Mo, W, Nb, Ta; X=S, Se, Te)
• Low-symmetry topological materials for large charge-to-spin interconversion: The case of transition metal dichalcogenide monolayers
• Tuning the Many-body Interactions in a Helical Luttinger Liquid
• Direct observation of topological surface state in the topological superconductor 2M-WS2
• Growth and Thermo-driven Crystalline Phase Transition of Metastable Monolayer 1T'-WSe2 Thin Film
• Anisotropic properties of monolayer 2D materials: an overview from the C2DB database
• Epitaxial Growth of Quasi-One-Dimensional Bismuth-Halide Chains with Topological Non-Trivial Edge States
• Strain tuned topology in the Haldane and the modified Haldane models
• Topology hierarchy of transition metal dichalcogenides built from quantum spin Hall layers
• Surface charge-transfer doping a quantum-confined silver monolayer beneath epitaxial graphene
• Observation of highly anisotropic bulk dispersion and spin-polarized topological surface states in CoTe2
• Room-temperature quantum spin Hall phase in laser-patterned few-layer 1T'- MoS2
• Realistic tight-binding model for monolayer transition metal dichalcogenides in 1T' structure
• Charge order with unusual star-of-David lattice in monolayer NbTe2
• Ultrafast Momentum-resolved Hot Electron Dynamics in the Two-dimensional Topological Insulator Bismuthene
• Structural phase transition in monolayer gold(I) telluride: From a room-temperature topologicalinsulator to an auxetic semiconductor
• Spontaneous breaking of time-reversal symmetry at the edges of 1T' monolayer transition metal dichalcogenides
• Engineering Topological quantum dot through planar magnetization in bismuthene
• Edge States of α-Bismuthene Nanostructures
• Band manipulation and spin texture in interacting moiré helical edges
• Temperature effects in topological insulators of transition metal dichalcogenide monolayers
• Anomalously high supercurrent density in a two-dimensional topological material
• Discovery of smectic charge and pair-density-wave orders in topological monolayer 1T${}^{\prime }$-MoTe${}_2$
• Functionalized Tellurene; a candidate large-gap 2D Topological Insulator
• Recipe for higher-order topology on the triangular lattice
• Robust Coulomb Gap and Varied-temperature Study of Epitaxial 1T'-WSe${}_2$ Monolayers
• Selective Fabrication of Monolayer 1H- and 1T'-WTe2
• Electronic structure of 2D van der Waals crystals and heterostructures investigated by spatially- and angle-resolved photoemission
• Role of interface hybridization on induced superconductivity in 1T${}^{\prime }$-WTe${}_2$ and 2H-NbSe${}_2$ heterostructures
• Exploring Topological Transport in Pt${}_2$HgSe${}_3$ Nanoribbons: Insights for Spintronic Device Integration
• Symmetry-breaking and spin-blockage effects on carrier dynamics in single-layer tungsten diselenide
• Quantum loops in the 1T transition metal dichalcogenides
• Finite-temperature spectroscopy of dirty helical Luttinger liquids
• Unusual temperature dependence of the band structure associated with local atomic distortion in monolayer 1T'-WTe2
• Emergent quantum phenomena in two-dimensional 1T-TaS2