Magnetic electrodes for spin-polarized injection into InAs

Tailored magnetic electrodes are an important prerequisite to inject and de tect charge carriers into a semiconductor with defined spins. Especially, i f a gate electrode is used to tune the polarization of the carriers by the Rashba effect, magnetic electrodes providing simultaneously a high degree o f polarization and a low stray field are important. We have simulated magne tization and hysteresis curves of permalloy electrode configurations and ve rified our theoretical results by magnetic-force microscopy for electrodes prepared on p-type InAs single crystals. This semiconductor exhibits a stro ng, gate-voltage dependent Rashba effect and therefore is a candidate for t he realization of the spin transistor. (C) 2000 American Institute of Physi cs. [S0003-6951(00)02610-3].