ABSTRACT
This chapter discusses the conversion of pure spin currents into a net electric current by application of an external field which provides an experimental access to the zero-bias spin separation. It considers various microscopic mechanisms of the spin photocurrent formation. Pure spin currents resulting in the zero-bias spin separation come from asymmetry of the electron scattering in gyrotropic semiconductor structures. The Zeeman effect disturbs the balance between electron flows of opposite spins caused by the relaxation mechanism resulting in a net photocurrent. Spin polarization of magnetic ions not only enhances the spin photocurrent due to the giant Zeeman effect but also disturbs the balance between electron flows with opposite spins due to spin-dependent scattering by localized magnetic ions. Spin photocurrents provide an experimental access to symmetry of lowdimensional structures. In gyrotropic semiconductor structures spin-dependent asymmetry of electron scattering induces a pure spin current which results in the zero-bias spin separation.
