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DOE OSTI · 1831504

Quantum Spin-Valley Hall Kink States: From Concept to Materials Design

Zhou, Tong·Cheng, Shuguang·Schleenvoigt, Michael·Schüffelgen, Peter·Jiang, Hua·Yang, Zhongqin·Žutić, Igor
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Abstract

We propose a general and tunable platform to realize high-density arrays of quantum spin-valley Hall kink (QSVHK) states with spin-valley-momentum locking based on a two-dimensional hexagonal topological insulator. Through the analysis of Berry curvature and topological charge, the QSVHK states are found to be topologically protected by the valley-inversion and time-reversal symmetries. Remarkably, the conductance of QSVHK states remains quantized against both nonmagnetic short- and long-range and magnetic long-range disorder, verified by the Green-function calculations. Based on first-principles results and our fabricated samples, we show that QSVHK states, protected with a gap up to 287 meV, can be realized in bismuthene by alloy engineering, surface functionalization, or electric field, supporting nonvolatile applications of spin-valley filters, valves, and waveguides even at room temperature.

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Zhou, Tong, Cheng, Shuguang, Schleenvoigt, Michael, Schüffelgen, Peter, Jiang, Hua, Yang, Zhongqin, Žutić, Igor. 2021-09-09. Quantum Spin-Valley Hall Kink States: From Concept to Materials Design. https://doi.org/10.1103/physrevlett.127.116402

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