Spin-polarized electron injection from ferromagnet into semiconductor

Summary form only given. Spin-polarized electron injection (spin injection) in ferromagnet/semiconductor (FM/SC) heterostructures is one of the key issues to realize spin-related devices. However, efficient spin injection in the FM/SC heterostructure remains a challenging task, although it is one of the promising candidates for spin-related devices, operating at room temperature. The only successful result was obtained in the case of diluted magnetic semiconductor (DMS). Furthermore, several theoretical reports predict that high efficiency spin injection is hardly possible in the FM/SC heterostructure due to conductivity mismatch between ferromagnet and semiconductor. Recently, high efficiency spin injection in an Fe/GaAs heterostructure was demonstrated by using a Schottky tunneling barrier. In this paper, we demonstrate that direct spin injection in an Fe/InAs heterostructure. InAs is a promising material for spin-related devices, because it is expected to form an ohmic contact to metal, and it has the larger spin-orbit coupling in an InAs 2DEG channel than in GaAs.