Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal

Abstract

The field of topological insulators (TI) was sparked by the prediction of the quantum spin Hall effect (QSHE) in time reversal invariant systems, such as spin-orbit coupled monolayer graphene. Ever since, a variety of monolayer crystals have been proposed as two-dimensional (2D) TIs exhibiting the QSHE, possibly even at high temperatures. However, conclusive evidence for a monolayer QSHE is still lacking, and systems based on semiconductor heterostructures operate at temperatures close to liquid helium. Here we report the observation of the QSHE in monolayer WTe2 at temperatures up to 100 Kelvin. The monolayer exhibits the hallmark quantized transport conductance, ~ e2/h per edge, in the short edge limit. Moreover, a magnetic field suppresses the conductance, and the observed Zeeman-type gap indicates the existence of a Kramers degenerate point, demonstrating the importance of time reversal symmetry for protection from elastic backscattering. Our results establish the high-temperature QSHE and open a new realm for the discovery of topological phases based on 2D crystals.

11 pages of maintext + 16 pages of supplementary materials

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Cited by in corpus (27)

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• Observation of a Majorana zero mode in a topologically protected edge channel
• Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T'-WTe2
• Toward Realistic Amorphous Topological Insulators
• Nonlinear magnetotransport shaped by Fermi surface topology and convexity in WTe2
• Direct evidence for charge compensation induced large magnetoresistance in thin WTe2
• Exploring Topological Superconductivity in Topological Materials
• Electronic properties of type-II Weyl semimetal WTe${}_2$. A review perspective
• Stanene: A Good Platform for Topological Insulator and Topological Superconductor
• Experimental Progress on Layered Topological Semimetals
• Directional massless Dirac fermions in a layered van der Waals material with one-dimensional long-range order
• Fractional Conductance in Strongly Interacting 1D Systems
• A Cleanroom in a Glovebox
• Mesoscopic transport in two-dimensional topological insulators
• Observation of Shubnikov-de Haas Oscillations in Large-Scale Weyl Semimetal WTe2 Films
• Dimensionality reduction and band quantization induced by potassium intercalation in 1$T$-HfTe${}_2$
• Hinged Quantum Spin-Hall Effect in Antiferromagnetic Topological Insulators
• Observation of backscattering induced by magnetism in a topological edge state
• Crossover Between Weak Antilocalization and Weak Localization and Electron-Electron Interaction in Few-Layer WTe${}_2$
• Room-temperature quantum spin Hall phase in laser-patterned few-layer 1T'- MoS2
• Living on the edge: Topology, electrostatics and disorder
• Raman spectrum of 1T'-WTe2 under tensile strain: A first-principles prediction
• Finite frequency backscattering current noise at a helical edge
• Electronic structure of molecular beam epitaxy grown 1T${}^{\prime }$-MoTe${}_2$ film and strain effect
• Fractional Josephson Effect: A Missing Step Is A Key Step
• Thermoelectric transport in two-dimensional topological insulator state based on HgTe quantum well
• Engineering chiral edge states in 2D topological insulator/ferromagnetic insulator heterostructures