Electron Transport at the Interface Between a Ferromagnetic Insulator and a Topological Insulator

Abstract

We perform a theoretical study of the electron transport through a normal metal-topological insulator-normal metal (NM-TI-NM) system, where a ferromagnetic insulator (FI) layer is deposited on top of the TI. The spin conductance of the system is analyzed as a function of parameters such as the strength of exchange coupling between the surface states of the TI and the magnetic moments of the FI layer, as well as the dimension of the TI channel. We find that the strength of the spin conductance can be optimized by tuning the parameters.