Spin splitting induced circular photocurrent in quantum wells

A theory of the circular photogalvanic effect caused by spin splitting in quantum wells is developed. Direct interband transitions between the hole and electron size-quantized subbands are considered. The photocurrent excitation spectrum is shown to depend strongly on the form of the spin–orbit interaction. In the case of structure inversion asymmetry induced (Rashba) spin splitting, it is a linear function of light frequency near the absorption edge. In contrast, when the bulk inversion asymmetry (Dresselhaus splitting) dominates, the photocurrent edge behavior is parabolic.