Direct conversion of light-polarization information into electric voltage using photoinduced inverse spin-Hall effect in Pt/GaAs hybrid structure: Spin photodetector

The direct conversion of light-polarization information into electric voltage has been demonstrated using the photoinduced inverse spin-Hall effect in a Pt/GaAs hybrid structure. In the GaAs layer, spin-polarized carriers are generated by the illumination of circularly polarized light, which induces a pure-spin current in the Pt layer through the interface. The pure-spin current is converted into an electromotive force using the inverse spin-Hall effect (ISHE) in the Pt layer. The electromotive force due to the photoinduced ISHE was found to be proportional to the degree of circular polarization of the illuminated light outside the sample in spite of the presence of the Pt top layer, which is consistent with a calculation based on the analysis for light propagation in multilayer structures. This conversion of light-polarization information into electric voltage works at room temperature without bias voltage and magnetic fields, and thus can be used as a spin photodetector. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3418441]