Anomalous-circular photogalvanic effect in a GaAs/AlGaAs two-dimensional electron gas

We have studied the circular photogalvanic effect (CPGE) in a GaAs/AlGaAs two-dimensional electron gas excited by near infrared light at room temperature. The anomalous CPGE observed under normal incidence indicates a swirling current which is realized by a radial spin current via the reciprocal spin-Hall effect. The anomalous CPGE exhibits a cubic cosine dependence on the incidence angle, which is discussed in line with the above interpretation.

National Natural Science Foundation of China 60625402 10804105973 programme 2006CB604908 2006CB921607 The authors thank Dr Y C Su and J H Yao for the growth of the sample. The work was supported by the National Natural Science Foundation of China (Nos 60625402 and 10804105) and the 973 programme (2006CB604908 2006CB921607).