Injection and detection of spin current and spin Hall effect in GaAs

A spin current is optically generated in GaAs and is detected by the spin Hall effect based on the extraordinary Hall effect. When photogenerated spin-polarized electrons are injected into the nonmagnetic semiconductor device by dragging them by a moderate electric field (0.35–1.20 kV/cm), a spin Hall voltage (transverse electric field) of 0.41 μV is obtained due to the induced nonequilibrium magnetization, which is proportional to the spin current in GaAs. The findings resulting from this experiment might have practical applications in the field of spintronics.