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arXiv · 2211.06443

Fast electrically switchable large gap quantum spin Hall states in MGe$_2$Z$_4$

Rajibul Islam·Ghulam Hussain·Rahul Verma·Mohammad Sadegh Talezadehlari·Zahir Muhammad·Bahadur Singh·Carmine Autieri
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Abstract

Spin-polarized conducting edge currents counterpropagate in quantum spin Hall (QSH) insulators and are protected against disorder-driven localizations by the time-reversal symmetry. Using these spin-currents for device applications require materials having large band gap and fast switchable QSH states. By means of in-depth first-principles calculations, we demonstrate the large band gap and fast switchable QSH state in a newly introduced two-dimensional (2D) material family with 1T$^\prime$-MGe$_2$Z$_4$ (M = Mo or W and Z = P or As). The thermodynamically stable 1T$^\prime$-MoGe$_2$Z$_4$ monolayers have a large energy gap around $\sim$237 meV. These materials undergo a phase transition from a QSH insulator to a trivial insulator with a Rashba-like spin splitting under the influence of an out-of-plane electric field, demonstrating the tunability of the band gap and its band topology. Fast topological phase switching in a large gap 1T$^\prime$-MoGe$_2$Z$_4$ QSH insulators has potential applications in low-power devices, quantum computation, and quantum communication.

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Rajibul Islam, Ghulam Hussain, Rahul Verma, Mohammad Sadegh Talezadehlari, Zahir Muhammad, Bahadur Singh, Carmine Autieri. 2022-11-11. Fast electrically switchable large gap quantum spin Hall states in MGe$_2$Z$_4$. https://doi.org/10.1002/aelm.202300156

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