Observation of the photoinduced anomalous Hall effect spectra in insulating InGaAs/AlGaAs quantum wells at room temperature

The photocurrent spectra of inter-band photoinduced anomalous Hall effect (AHE) in insulating InGaAs/AlGaAs quantum wells have been observed at room temperature. The AHE current changes linearly with longitudinal electric fields. The anomalous Hall conductivity corresponding to excitonic state 1HH-1E (the first valence subband of heavy hole to the first conduction) has the same sign with that of excitonic state 1LH-1E, while the sign inverses when the photon energy is larger than the excitonic state 1LH-1E. The reason for this interesting phenomenon has been discussed. Due to the strong Rashba spin-orbit coupling in this perfect crystal, the photoinduced AHE is supposed to be intrinsic.