9409049 Smith This project uses a variety of time-resolved spectroscopic techniques to shed some light on the dynamics of the exchange interactions in II-VI semiconductors between electrons, holes and magnetic impurities, as well as among the impurities themselves. The goals of this research are the following: (1) to study the dynamics of formation and decay of exciton magnetic polarons in different dimensional configurations, (2) to measure the relative strength and spatial scale of the Manganese-Iron interaction in Manganese doped Zinc-Selenium and Iron doped Zinc-Selenium structure, (3) to measure optically the spatial diffusion of a local perturbation of the magnetic spins in order to gain new information on exchange interaction between the magnetic impurities, and (4) to measure directly the effect of valence band mixing on spin-relaxation rate. % % % % The recent development of blue solid state lasers using Zinc- Selenide has increased the need for understanding the basic physics of elementary interactions in these materials. In particular, the basic relaxation mechanisms of highly excited electronic states in these materials is directly applicable to the engineering of new higher-efficiency laser-diodes. This project will use a variety of novel time-resolved optical spectroscopies to study the interaction between electrons holes and magnetic impurities in wide-gap Zinc- Selenide-based semiconductors. In particular, we hope to gain understanding on how the spins in these materials lose energy and eventually form new confined states, as well as how the magnetic interactions in these materials affect the transport properties of electrons and holes. ***
