Department of Physics, Northwest University, Xi'an 710069, People's Republic of China.
J Phys Condens Matter. 2013 Feb 20;25(7):075304. doi: 10.1088/0953-8984/25/7/075304. Epub 2013 Jan 23.
We theoretically investigate the electronic transport between quantum Hall states and quantum anomalous Hall states in a zigzag edged graphene nanoribbon based two-terminal heterojunction. The electrical conductance of the system is calculated by the method of the non-equilibrium Green's function and Landauer-Büttiker formula. We find perfect transmission through the junction when the propagation direction of the charge carriers is the same at the same edge in both regions. However, when the propagation direction at the same edge is the opposite, the electrical conductance is smaller than the quantized value. In this case, snake states at the interface are responsible for the transmission. The results are explained with the aid of the local density of states near the interface. For higher magnetic field in the quantum Hall region or larger ribbon width, the edge states are better realized and quantized electrical conductance is strengthened. Finally, the effects of Anderson disorder and dephasing on the transmission are discussed.
我们从理论上研究了基于锯齿形边缘石墨烯纳米带的两端异质结中量子霍尔态和量子反常霍尔态之间的电子输运。通过非平衡格林函数和朗道-比尔特定律的方法计算了系统的电导。当载流子在两个区域中的同一边缘的传播方向相同时，我们发现通过结的完全传输。然而，当同一边缘的传播方向相反时，电导小于量子化值。在这种情况下，界面处的蛇态负责传输。通过界面附近的局域态密度解释了结果。对于量子霍尔区的更高磁场或更大的带状宽度，边缘态更好地实现并且量化的电导得到增强。最后，讨论了安德森无序和退相位对传输的影响。
