Transverse electric current induced by optically injected spin current in cross-shaped InGaAs/InAlAs system

We examine electric response of a linearly polarized light normally shed on a cross-shaped quasi 2-dimensional InGaAs/InAlAs system with structure inversion asymmetry. The photo-excited conduction electrons carry a pure spin current with in-plane spin polarization due to the Rashba spin-orbit interaction. We use Landauer-B\"{u}ttiker formalism to show that this spin current induces two inward or outward transverse charge currents, which are observable in experiments. This effect may serve as an experimental probe of certain types of spin current.