Spin galvanic effect between subband of InGaAs/AlGaAs 2DEG

We report the electric current induced by optically injected spin current on the vicinity of a crossbar shaped InGaAs/AlGaAs two dimensional electronic gas (2DEG) without external electric or magnetic field at room temperature. The electric current is either both in-ward or both out-ward flowing through the crossbar, while the total Hall voltage or current remains negligibly. The geometric size, temperature and external magnetic field dependence of the electric current have been examined and the corresponding mechanism has been discussed.