Valley Edelstein Effect in Monolayer Transition Metal Dichalcogenides

Katsuhisa Taguchi, Yuki Kawaguchi, Yukio Tanaka, Kam Tuen Law

Published 2017-05-23Version 1

Monolayer transition metal dichalcogenides (MTMDs) exhibit spin-orbit coupling (SOC) called Ising SOC which polarizes electron spins to opposite out-of-plane directions for electrons in opposite valleys. We predict the emergence of the valley Edelstein Effect (VEE), which is an electric-field-induced spin polarization effect, in the MTMDs. We found an unconventional valley-dependent response in which the spin-polarization is parallel to the applied electric field and the spin-polarization is opposite at opposite valleys due to the Ising SOC. This is in sharp contrast to usual Edelstein effect in which the induced spin-polarization is perpendicular to the applied electric field. We attribute the VEE to the valley Hall effect and Ising SOC. Experimental schemes to detect the VEE are also considered.