Optically injected spin current in [110] GaAs quantum wells

The optical injection of spin current with out-of-plane polarization is investigated in the [110]-grown semiconductor quantum well by irradiation of polarized light via inter-band excitations. Due to spin–orbit coupling, the normally incident linearly polarized light can pump the electrons from valence band to conduction band and inject pure spin current with out-of-plane polarization, while a photocurrent can be induced by circularly polarized light. The amplitude of the optically injected spin current can be deduced from the experimentally measured photocurrent and material specific parameters.