Enhanced spin hall effect in semiconductor heterostructures with artificial potential

We theoretically investigate the extrinsic spin Hall effect (SHE) in semiconductor heterostructures, caused by scattering at an artificial potential created by an antidot, STM tip, etc. The potential is electrically tunable. First, we formulate the SHE in terms of phase shifts in the partial wave expansion for a two-dimensional electron gas. The effect is significantly enhanced by resonant scattering when the attractive potential is properly tuned. Second, we examine a three-terminal device including an antidot, which possibly produces a spin current with a polarization of more than 50%.