Spin-charge transport driven by magnetization dynamics on disordered surface of doped topological insulators

TL;DR

This paper presents a theoretical study of how magnetization dynamics induce spin and charge currents on the disordered surface of doped topological insulators, highlighting both local and nonlocal effects.

Contribution

It introduces a comprehensive theoretical framework for understanding spin-charge transport driven by magnetization dynamics on disordered topological insulator surfaces, including nonlocal effects.

Findings

Spin and charge currents are induced by local and nonlocal magnetization dynamics.

Spin current and charge density are generated by spatially inhomogeneous magnetization.

Spin current diffusively propagates on the disordered surface.

Abstract

We theoretically study the spin and charge generation along with the electron transport on a disordered surface of a doped three-dimensional topological insulator/magnetic insulator junction by using Green's function techniques. We find that the spin and charge current are induced by not only local but also nonlocal magnetization dynamics through nonmagnetic impurity scattering on the disordered surface of the doped topological insulator. We also clarify that the spin current as well as charge density are induced by spatially inhomogeneous magnetization dynamics, and the spin current diffusively propagates on the disordered surface. Using these results, we discuss both local and nonlocal spin torques before and after the spin and spin current generation on the surface, and provide a procedure to detect the spin current.