Molecular beam epitaxy of semiconductor heterostructures for spintronics

In this dissertation, we use molecular beam epitaxy to engineer a variety of materials of relevance to the emerging research field known as semiconductor spintronics. The broad aim of this research is to establish a fundamental framework that exploits electronic spin states in semiconductors for the manipulation, transfer, detection and storage of information.; We begin this dissertation by discussing the underlying basis for diluted magnetic semiconductors. We then follow this with a discussion of experimental studies of the crystal growth and physical properties of a "canonical" case: Ga1-xMnxAs. We then highlight an important advance achieved during this dissertation, namely the identification of growth and annealing parameters that result in samples with consistently reproducible Curie temperatures up to 150 K.; We next consider heterostructures that integrate Ga1- xMnxAs with other materials, including the fabrication of Ga1-xMn xAs on ZnSe(001) using a recrystallized GaAs template. It is found that n-doping of ZnSe using Cl does not affect the ferromagnetism of Ga1-xMnxAs, paving a pathway to potential applications with Ga1- xMnxAs/ZnSe heterostructures. We then demonstrate efficient spin-polarization tunneling between a ferromagnetic metal and a ferromagnetic semiconductor using epitaxial magnetic tunnel junctions composed of a ferromagnetic metal (MnAs) and a ferromagnetic semiconductor (Ga1-xMnxAs) separated by a non-magnetic semiconductor (AlAs).; Finally we turn our attention to conventional non-magnetic semiconductor heterostructures in which spin polarization is introduced via optical pumping. The effect of different crystallographic orientations on spin relaxation processes in modulation-doped ZnSe quantum wells is examined. We finish this dissertation with a briefly discussion of the future direction of coherent control of electron g-factor using magnetic ZnSe parabolic quantum wells. (Abstract shortened by UMI.)...