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. (C) 2008 Elsevier Ltd. All rights reserved.