拓扑绝缘体表面台阶势垒的输运性质

Transport properties of step barrier on the surface of a topological insulator

利用传递矩阵的方法研究拓扑绝缘体表面台阶势垒的输运性质,发现台阶势垒的形状明显地影响了拓扑绝缘体表面的输运性质。拓扑绝缘体表面存在克莱因隧穿,透射概率取决于势垒的高度。随着费米能级的变化,电导出现了共振隧穿现象;而随着台阶势垒高低势能差的变化,电导出现了开关效应,可以通过调节费米能级和台阶势垒高低势能差来控制电导。

The transport properties of step barrier on the surface of topological insulator are studied using transfer matrix method.It is found that the height of the step barrier influences the transport properties.Klein tunneling appears on the surface of a topological insulator and the transmission probability is depended on the height of the step barrier.The conductances show resonant tunneling behavior as the Fermi energy varies,and the switching effect can be obtained in the conductances as the difference of the height of the step barrier varies.So the conductance can be controlled by adjusting the Fermi energy and the difference of height of the step barrier.