Zusammenfassung

The circular photogalvanic effect, induced by infrared radiation, has been observed in (0001)-oriented n-GaN low dimensional structures. The photocurrent changes sign upon reversing the radiation helicity demonstrating the existence of spin splitting of the conduction band in k space in this type of materials. The observation suggests the presence of a sizeable Rashba type of spin splitting, caused by the built-in asymmetry at the AlGaN/GaN interface. (c) 2005 American Institute of Physics.