Voltage-tunable spin electron beam splitter based on antiparallel double δ-magnetic-barrier nanostructure

We report on a theoretical study of spin-dependent Goos-Hanchen (GH) shift of electrons in antiparallel double delta-magnetic-barrier (MB) nanostructure under an applied voltage, which can be experimentally realized by depositing two metallic ferromagnetic (FM) stripes on top and bottom of the semiconductor heterostructure. GH shifts for spin electron beams across this device, is exactly calculated, with the help of the stationary phase method. It is shown that a considerable spin polarization of GH shifts can be achieved in this device for two delta-MBs with unidentical magnetic strengths. It also is shown that both magnitude and sign of spin polarization of GH shifts can be controlled by adjusting the electric potential induced by the applied voltage. These interesting properties may provide an effective approach of spin injection for spintronics application, and this device can be used as a voltage-tunable spin beam splitter. (C) 2011 Elsevier B.V. All rights reserved.