DILUTED MAGNETIC SEMICONDUCTORS AS A TOOL FOR WAVE-FUNCTION MAPPING IN SEMICONDUCTOR HETEROSTRUCTURES

Conduction and valence band edges in diluted magnetic semiconductors ( e.g., Zn1-xMnxSe) undergo enormous Zeeman shifts when a magnetic field is applied, reaching values in excess of 100 meV at low temperatures. By performing magneto-optical studies on semiconductor heterostructur es consisting of diluted magnetic and non-magnetic layers (e.g., a ZnM nSe/ZnSe superlattice), one can exploit the drastic differences in the Zeeman splitting occurring in different layers to pinpoint the locali zation in space of specific electronic states. In particular, we discu ss the spatial localization of states whose energy exceeds the potenti al barriers. We illustrate this by the investigation of above-barrier excitons localized in the barriers of type-I ZnSe/ZnMnSe superlattices , and of type-I (spatially direct) excitons in ZnTe/CdMnSe and ZnMnTe/ CdSe type-II superlattices. We also discuss quasi-localization of stat es in a single barrier.