论文标题
拓扑边缘状态下的随机门网电压诱导的Al'tshuler-Aronov-Spivak效应
Random-gate-voltage induced Al'tshuler-Aronov-Spivak effect in topological edge states
论文作者
论文摘要
螺旋边缘状态是量子旋转厅绝缘子的标志。最近，几个实验观察到了由微不足道的边缘状态造成的运输特征，因此很难区分拓扑琐碎的阶段。在这里，我们表明，可以通过随机门电压诱导的$φ_0/2 $ - 周期振荡来识别螺旋边缘状态，平均电子返回概率在边缘状态构建的干涉仪中。随机门电压可以通过淬灭$ \ sin^2（2πφ/φ_0）$来突出显示$φ_0/2 $ - period al'tshuler-aronov-spivak振荡，通过淬灭$φ_0$ -period $ -period -period-period aharonov-aharonov-aharonov-bohm oscillation。发现螺旋自旋纹理引起的$π$浆果相对于如此弱的抗静脉化行为是关键，而零回报概率为$φ= 0 $。相反，根据自旋轨道耦合的强度，琐碎边缘状态的振荡可能表现出弱定位或抗静脉化，后者的强度为$φ= 0 $。我们的结果为识别螺旋边缘状态提供了有效的方法。预测的签名通过时间反转对称性稳定，因此它具有鲁棒性，并且不需要对系统进行任何精细的调整。
Helical edge states are the hallmark of the quantum spin Hall insulator. Recently, several experiments have observed transport signatures contributed by trivial edge states, making it difficult to distinguish between the topologically trivial and nontrivial phases. Here, we show that helical edge states can be identified by the random-gate-voltage induced $Φ_0/2$-period oscillation of the averaged electron return probability in the interferometer constructed by the edge states. The random gate voltage can highlight the $Φ_0/2$-period Al'tshuler-Aronov-Spivak oscillation proportional to $\sin^2(2πΦ/Φ_0)$ by quenching the $Φ_0$-period Aharonov-Bohm oscillation. It is found that the helical spin texture induced $π$ Berry phase is key to such weak antilocalization behavior with zero return probability at $Φ=0$. In contrast, the oscillation for the trivial edge states may exhibit either weak localization or antilocalization depending on the strength of the spin-orbit coupling, which have finite return probability at $Φ=0$. Our results provide an effective way for the identification of the helical edge states. The predicted signature is stabilized by the time-reversal symmetry so that it is robust against disorder and does not require any fine adjustment of system.
