论文标题
三维量子厅系统的无电导
Thouless conductances of a three-dimensional quantum Hall system
论文作者
论文摘要
我们使用数值的TH TH TUCTIONCE计算研究了无序的三维（3D）量子厅系统的纵向电导。对于批量，我们确认移动性边缘与此各向异性系统中的传播方向无关。随着疾病的增加，水平方向上最低子带的电导峰如二维（2D）情况一样漂浮到中央子带，而没有明确的证据表明垂直方向漂浮。因此，我们得出的结论是，对于扩展状态，垂直方向的纵向电导的行为就像准二维（1D）正常金属，而水平方向的纵向电导均通过分层导电状态相干地控制。在量子大厅间隙内，我们研究了样品侧壁的新型2D手性表面状态。我们证明了准金属和绝缘体状态之间表面状态的交叉，这可以通过修改模型中的层间跳和混乱强度来实现。研究了这两个方案中无电导的典型行为和表面状态的波函数。最后，为了预测表面状态的任意参数的状态，我们确定了表面状态的定位长度与模型的显微镜参数之间的明确关系。
We investigate the longitudinal conductance of a disordered three-dimensional (3D) quantum Hall system within a tight-binding lattice model using numerical Thouless conductance calculations. For the bulk, we confirm that the mobility edges are independent of the propagating directions in this anisotropic system. As disorder increases, the conductance peak of the lowest subband in the horizontal direction floats to the central subband as in the two-dimensional (2D) case, while there is no clear evidence of floating in the vertical direction. We thus conclude that for extended states, the longitudinal conductance in the vertical direction behaves like a quasi-one-dimensional (1D) normal metal, while the longitudinal conductance in the horizontal direction is controlled by layered conducting states stacked coherently. Inside the quantum Hall gap, we study the novel 2D chiral surface states at the sidewalls of the sample. We demonstrate the crossover of the surface states between the quasi-1D metal and insulator regimes, which can be achieved by modifying the interlayer hopping strength and the disorder strength in the model. The typical behaviors of the Thouless conductance and the wave functions of the surface states in these two regimes are investigated. Finally, in order to predict the regime of the surface states for arbitrary parameters, we determine an explicit relationship between the localization length of surface states and the microscopic parameters of the model.
