The influence of inelastic relaxation time on intrinsic spin Hall effects in a disordered two-dimensional electron gas

The influence of inelastic relaxation time on the intrinsic spin Hall effects in a disordered two-dimensional electron gas with Rashba interaction is studied; we clarify the controversy as regards impurity effects in the system. We reveal that, due to the existence of inelastic scattering, the spin Hall conductivity does not vanish when the impurity concentration diminishes to zero, regardless of nonmagnetic or magnetic disorder. The spin accumulation is evaluated by using the spin Hall conductivity obtained, and an alternative route is suggested for verifying the intrinsic spin Hall effect by measuring the spin accumulation at different ratios.