SPIN DYNAMICS AND DIMENSIONALITY IN DILUTED MAGNETIC SEMICONDUCTORS

A parallel set of two low-temperature optical experiments are performed to explore the connection between magnetic and electronic properties in Cd1-xMn(x)Te diluted magnetic semiconductor quantum structures. Using a combination of integrated DC SQUIDs and ultrafast optical techniques, dynamical measurements reveal the magnetic manifestations of carrier scattering and localization in quantum wells. These magnetic spectroscopy studies show entirely different time scales for magnetic interactions as compared to electronic spin behavior, and are seen to persist long after the carriers have disappeared from the system. In addition, femtosecond spin-polarized luminescence experiments record unexpectedly rapid electronic spin scattering of charge carriers (< 150 fs) with a dramatic dependence of these times on the dimensionality.