Branching-induced spin polarization amplification in nonmagnetic semiconductors

Abstract

We study the spin injection in ferromagnet-tunnel barrier-semiconductor heterojunction structure embedded in the current-branching scheme. The current branching enables one to separately control the charge current from the spin current. As a result, it is possible to electrically control the spin current polarization within the semiconductor. Moreover, it can be enhanced further and may reach 100% by properly tuning the branched currents. Since the proposed scheme does not require low temperature operation, it may be a useful tool to generate the high spin current polarization at room temperature. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim