One-way transmission of electrons on the topological insulator surface modulated by magnetic potential

摘要

We investigate the transport properties of Dirac fermions on the surface of a three-dimensional topological insulator (TI) with magnetic modulation potentials. By using the transfer-matrix method, the transmission coefficients are obtained as a function of incident energy and incident angle. It is shown that the forward and backward propagating carriers possess different transmission coefficients at some incident energies when the charge carriers incident obliquely, which originates from the break of time reversal symmetry. Particularly, the magnetic barrier introduces asymmetric scattering; thus, the scattered angles are different for the forward and backward propagating carriers. As a consequence, the transmission in one direction is permitted while it is blocked in its reversal direction. Therefore, the unidirectional transmission of electrons is achieved on the surface of TI. Furthermore, unidirectional transmission is demonstrated by the electronic charge distributions in the system. The investigations may have potential applications in the design of TI-based one-way quantum devices.