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 either nonmagnetic or long-range magnetic disorder, verified by the Green function calculations. Based on first-principles results, 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 non-volatile applications of spin-valley filters, valves, and waveguides even at room temperature.
@article{arxiv.2102.05806,
title = {Quantum Spin-Valley Hall Kink States: From Concept to Materials Design},
author = {Tong Zhou and Shuguang Cheng and Michael Schleenvoigt and Peter Schuffelgen and Hua Jiang and Zhongqin Yang and Igor Zutic},
journal= {arXiv preprint arXiv:2102.05806},
year = {2021}
}