Edelstein effect in pseudospin Dirac systems

Abstract

Edelstein effect of spin polarization means an electric field could induce a magnetization in nonmagnetic materials. This effect can be well understood by a Zeeman-like term due to an effective magnetic field in spin-orbit coupling systems. We propose a mechanism of current-induced spin polarization, where the real spin is not directly related to the effective magnetic field induced by an electric field. This effective field only results in the polarization of a general spin. Then the real spin polarization is generated through the coupling between the real spin and the general spin in pseudospin Dirac systems with low symmetry. The values of our spin polarization and the conventional one may have the same order of magnitude though ours involves two processes, which has been further verified by the numerical calculation in the $1{T}^{\ensuremath{'}}\text{\ensuremath{-}}{\mathrm{WTe}}_{2}$ distorted monolayer. It will be helpful for the deeper understanding of the current-induced spin polarization in pseudospin Dirac materials.