Configuration-sensitive transport at the domain walls of a magnetic topological insulator

We study the transport at the domain wall (DW) in a magnetic topological insulator. The low-energy behaviors of the magnetic topological insulator are dominated by the chiral edge states (CESs). Here, we find that the spectrum and transport of the CESs at the DW are strongly dependent on the DW configuration. For a Bloch wall, two copropagating CESs at the DW are doubly degenerate, and the incoming electron is totally reflected. However, for a Neel wall, the two CESs are split, and the transmission is determined by the interference between the CESs. Moreover, the effective Hamiltonian for the CESs indicates that the component of magnetization perpendicular to the wall leads to the distinct transport behaviors. These findings may pave the way to realizing low-power-dissipation spintronics devices based on magnetic DWs.