Spin injection from a ferromagnetic electrode into InAs surface inversion layer

Summary form only given. We show that the spin injection from a ferromagnetic electrode into a surface inversion layer of InAs is possible without an external magnetic field, which is a promising step towards the realization of a spin transistor. Electron spin is attracting much interest in semiconductors in the hope that the manipulation of the spin-entangled state would eventually lead to a quantum computer with a semiconductor chip. There have been discussions on whether or not an-efficient spin injection into a semiconductor is possible at all. Experimentally, spin injection from diluted magnetic semiconductors has been reported, with the injection efficiency of /spl ap/1%. The spin injection from high Tc ferromagnetic metals into semiconductors has been reported recently, demonstrating approximately 2%-efficient spin-injection in a Fe/GaAs system where electrons tunnel through a Schottky barrier which would limit the drain current drastically. Here we show that the spin injection is possible without a tunneling barrier in an Fe/InAs hybrid structure with an injection efficiency of /spl sim/4%.