Pure spin current from one-photon absorption of linearly polarized light   in noncentrosymmetric semiconductors
  We show that one-photon absorption of linearly polarized light should produce pure spin currents in noncentrosymmetric semiconductors, including even bulk GaAs. We present 14x14 k.p model calculations of the effect in GaAs, including strain, and pseudopotential calculations of the effect in wurtzite CdSe. 
R. D. R. Bhat, F. Nastos, Ali Najmaie and J. E. Sipe