Abstract :
In this paper, the bias-dependent electron transport is investigated in detail in a magnetic double-barrier nanostructure in the presence of two bias voltages. It is shown that the large spin-polarization can be achieved in such a nanostructure, and the degree of the spin-polarization is strongly dependent on the applied bias. These interesting properties can provide an alternative scheme to spin-polarize electrons into semiconductors, and this device may be used as a bias-tunable spin filter.