Scattering Induced Spin Separation at Zero Bias

Zusammenfassung

We show that in gyrotropic semiconductor structures spin-dependent asymmetry of electron scattering induces a spin separation which, in contrast to the spin Hall effect, does not require an electric current to flow. The effect is observed in GaAs/AlGaAs quantum well structures at free-carrier absorption of terahertz (THz) radiation. Microscopic theory based on asymmetry of photoexcitation and relaxation is developed being in a good agreement with experiment.