Coherent spin dynamics and spin polarized transport in doped semiconductors

We provide an overview of measurements that elucidate the effects of interactions, quantum confinement, reduced dimensionality, and interfacial geometries on coherent electronic spin dynamics and spin transport in doped semiconductors. The experiments focus on a variety of doped semiconductor systems, ranging from bulk n-GaAs crystals to modulation doped II-VI magnetic semiconductor quantum wells. In particular, the latter provide model systems in which electron gases are strongly exchange-coupled to an engineered distribution of magnetic moments, hence allowing one to systematically tailor spin interactions between confined electronic states, magnetic ions, and nuclei. 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.