Spin dependent confinement effects in Cd0.9Mn0.1TeCd0.9Mg0.1Te spin superlattices

Abstract We have realized a spin superlattice structure based on a Cd 0.9 Mn 0.1 Te Cd 0.9 Mg 0.1 Te heterostructure, where the valence and the conduction band align with zero band offset. Due to the large spin-splitting of the conduction- and valence band-edges in the semimagnetic (CdMn)Te layer and the vanishing spin-splitting in the nonmagnetic (CdMg)Te layer a significant spatial separation of spin-up and spin-down carriers is achieved with increasing magnetic field strength. The formation of the spin superlattice is proved by the Zeeman pattern of the excitonic states. The Zeeman pattern directly reflects the energy shift of spin-up states localized in the nonmagnetic and spin-down states in the semimagnetic layers. In addition, the exciton magnetic polaron is used as a sensitive probe for the small confinement potentials controlled by the externally applied field, demonstrating the exciton localisation in the spin dependent quantum wells of a spin superlattice.