Spintronics, short notation for spin-based electronics, is a research area which seeks to exploit the spin of electrons in addition to their charge in semiconductors. The basic idea is to combine the characteristics of existing magnetic devices with semiconductor devices in order to realize a new generation of devices that are much smaller, more energy efficient, non-volatile, and much faster than presently available. The key requirement in the development of such devices is an efficient injection, transfer and detection of spin-polarized current from a ferromagnetic material into a...