Coherent spin dynamics and spin polarized transport in doped semiconductors

We provide an overview of measurements that elucidate the effects of intera ctions, quantum confinement, reduced dimensionality, and interfacial geomet ries on coherent electronic spin dynamics and spin transport in doped semic onductors. The experiments focus on a variety of doped semiconductor system s, ranging from bulk n-GaAs crystals to modulation doped II-VI magnetic sem iconductor quantum wells. In particular, the latter provide model systems i n which electron gases are strongly exchange-coupled to an engineered distr ibution of magnetic moments, hence allowing one to systematically tailor sp in interactions between confined electronic states, magnetic ions, and nucl ei. Two complementary techniques including state-of-the-art spin dynamical probes having high temporal (similar to 100 fs) and spatial (similar to 100 nm) resolution, and low-temperature magneto-transport, are used to survey a variety of physical phenomena in these systems.