Bias-tunable electron–spin polarization in an antiparallel double δδ-magnetic-barrier nanostructure

We present a theoretical study of spin-dependent electron transport in an antiparallel double δδ-magnetic-barrier nanostructure with an applied bias. It is shown that large spin-polarized current can be achieved in such a device with unidentical strength between two δδ-magnetic-barriers. It also is shown that the degree of electron–spin polarization is strongly dependent upon the applied bias. These interesting properties may provide an alternative scheme to spin-polarize electrons into semiconductors, and this device may be used as a bias-tunable spin filter.