Ultrafast extrinsic spin-Hall currents
  We consider the possibility of ultrafast extrinsic spin-Hall currents, generated by skew scattering following the optical injection of charge or pure spin currents. We propose a phenomenological model for this effect in quantum well structures. An injected charge current leads to a spin-Hall-induced pure spin current, and an injected pure spin current leads to a spin-Hall-induced charge current. The resulting spin or charge accumulation can be measured optically. 
E. Ya. Sherman, Ali Najmaie, H.M. van Driel, Arthur L. Smirl, and J.E.   Sipe