Orbital angular momentum driven intrinsic spin Hall effect
  We propose a mechanism of intrinsic spin Hall effect (SHE). In this mechanism, local orbital angular momentum (OAM) induces electron position shift and couples with the bias electric field to generate orbital Hall effect (OHE). SHE then emerges as a concomitant effect of OHE through the atomic spin-orbit coupling. Spin Hall conductivity due to this mechanism is estimated to be comparable to experimental values for heavy metals. This mechanism predicts the sign change of the spin Hall conductivity as the spin-orbit polarization changes its sign, and also correlation between the spin Hall conductivity and the splitting of the Rashba-type spin splitting at surfaces. 
Wonsig Jung, Dongwook Go, Hyun-Woo Lee and Changyoung Kim
cond-mat.mes-hall cond-mat.mtrl-sci