Spin hall effect in an inverted heterostructure

Spin-up and -down electrons experience skew scattering in a two-dimensional electron gas layer and two kinds of spin electrons deviate different directions due to the spin dependent deflection. If spin is randomly oriented, the number of scattered electrons 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.