Removal of spin degeneracy in SiGe-based nanostructures

Abstract

The photogalvanic effects, which require a system lacking inversion symmetry, become possible in SiGe based quantum well (QW) structures due to their built-in asymmetry. We report on the removal of spin degeneracy in the k-space of SiGe nanostructures. This is concluded from the observations of the circular photogalvanic effect induced by infrared radiation in asymmetric p-type QWs. We discuss possible mechanisms that give rise to spin-splitting of the electronic subband states.