Spin injection into semiconductors, physics and experiments

In this paper we review and extend our modelling of the physics governing electrical spin injection into non-magnetic semiconductors. A critical evaluation is given of several approaches to circumvent the impedance mismatch that prohibits spin injection in the diffusive transport regime, i.e. ballistic transport, the use of tunnel barriers and the physics of a Schottky contact. We conclude by discussing an experimental illustration of our modelling. In an all-electrical geometry, we utilize spin injection from a paramagnetic injector to demonstrate a novel magnetoresistance effect.