Voltage-controllable spin beam splitter based on realistic magnetic-barrier nanostructure.

ABSTRACT

We report a theoretical investigation on the Goos-Hänchen (GH) effect of spin electron beams in realistic magnetic-barrier (MB) nanostructures under an applied voltage, which can be experimentally created by lithographic patterning of ferromagnetic (FM) or superconducting films. GH shifts of spin electron beams are calculated numerically for the InAs material system, with the help of the stationary phase method. It is shown that a significant spin polarization effect can be induced by such MB nanostructures with symmetric magnetic field profiles. It also is shown that both magnitude and sign of the spin polarization is closely relative to the electric barrier (EB) produced by a constant voltage applied to the metallic FM stripe of system. These interesting properties may provide an alternative way to spin injection into the semiconductor, and such nanostructures can serve as voltage-tunable spin beam splitters.