Spin current and magnetization induced by circularly polarized synchrotron radiation in magnetically-doped topological insulator Bi$_{1.37}$V$_{0.03}$Sb$_{0.6}$Te$_2$Se

TL;DR

This paper demonstrates a hole-induced mechanism for generating spin-polarized currents and magnetization in magnetically-doped topological insulators using circularly polarized synchrotron radiation, supported by experimental and theoretical analysis.

Contribution

It introduces a novel hole-induced mechanism for spin current and magnetization generation in topological insulators under circularly polarized light.

Findings

Spin-polarized current relates to the shift in electrochemical potential.

Circular polarization induces out-of-plane magnetization.

Magnetization reverses with polarization switching.

Abstract

We propose a hole-induced mechanism of spin-polarized current generation by circularly polarized synchrotron radiation and corresponding induced magnetization in magnetically-doped topological insulators Bi$_{1.37}$V$_{0.03}$Sb$_{0.6}$Te$_2$Se. Considered spin-polarized current is generated due to the spin-dependent depopulation of the Dirac cone topological surface states at the Fermi level and subsequent compensation of the generated holes. We have found experimentally and theoretically a relation between the generated spin-polarized current and the shift of the electrochemical potential. The out-of-plane magnetization induced by circularly polarized synchrotron radiation and its inversion with switching the direction of circular polarization were experimentally shown and theoretically confirmed.