论文标题
快速电气切换大差距量子旋转大厅状态MGE $ _2 $ z $ _4 $
Fast electrically switchable large gap quantum spin Hall states in MGe$_2$Z$_4$
论文作者
论文摘要
自旋偏振电导电流在量子自旋大厅（QSH）绝缘子中逆时发性，并通过时间反转对称性受到疾病驱动的局部性的保护。将这些自旋电流用于设备应用需要具有较大的带隙和快速可切换QSH状态的材料。通过深入的第一原理计算，我们在新引入的二维（2D）材料家族中证明了较大的频段差距和快速可切换QSH状态，该状态具有1T $^\ PRIME $ -MGE $ -MGE $ _2 $ _2 $ _2 $ z $ _4 $（m = mo或w and w and w and z = p或as）。热力学稳定的1T $^\ PRIME $ -MOGE $ _2 $ z $ _4 $单层具有较大的能量差距，左右$ \ sim $ 237 mev。这些材料从QSH绝缘子到琐碎的绝缘子经历了相变，并在平面外电场的影响下进行了类似Rashba的旋转分裂，这表明了带隙及其带拓扑的可调性。快速拓扑阶段切换在大间隙1T $^\ prime $ -moge $ _2 $ z $ _4 $ QSH绝缘子中具有潜在的应用程序，可在低功率设备，量子计算和量子通信中进行。
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.
