Unbalanced spin accumulation induced by spin Hall effect

Abstract

Moving electrons of different spins experience skew scattering in a two-dimensional electron gas layer and the electron deviates different direction due to the spin-dependent deflection. If spin is randomly oriented, the amount of skew scattering on both sides will be same and the Hall voltage will read zero. In this experiment, the carrier concentrations of spin up and down are unbalanced because the spin is aligned by stray field from the ferromagnet. Therefore, the voltage probe reads charge accumulation asymmetry. Spin Hall voltage is functions of the spin alignment direction and the amount of spin polarization.