Optical Properties of Diluted Magnetic Semiconductor Quantum Structures
M. Dobrowolska, H. Luo and J.K. Furdyna
Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA
Full Text PDF
Conduction and valence band edges in diluted magnetic semiconductors undergo enormous Zeeman shifts when a magnetic field is applied, reach­ing values in excess of 100 meV at low temperatures. These Zeeman shifts can thus have profound consequences on the properties of DMS/non-DMS heterostructures, since they provide the opportunity of tuning their band alignment by varying an applied field. This leads to a variety of entirely new effects, and also provides a powerful tool for probing the effect of band alignment on the properties of semiconductor heterostructures in general. We illustrate this with several examples. First, using the ZnSe/ZnMnSe sys­tem, we discuss the creation of a spatial spin modulation (spin superlattice). Second, we use the drastic differences in the Zeeman splitting occurring in different layers of a DMS/non-DMS superlattice in order to pinpoint the localization in space of the specific electronic states involved in optical tran­sitions. We illustrate this by investigating the localization of above-barrier states in type-I ZnSe/ZnMnSe superlattices, and of spatially-direct (type-I) excitons which occur in ZnTe/CdMnSe and ZnMnTe/CdSe type-II super-lattices. Finally, we exploit Zeeman tuning to demonstrate the confinement effects which occur in a single quantum barrier.
DOI: 10.12693/APhysPolA.87.95
PACS numbers: 73.20.Dx, 75.30.Et, 78.20.Ls, 68.55.Bd