Spin-valley filtering induced by resonant states in silicene

We studied the spin and valley transport of silicene through a resonant-tunneling structure with electric field and magnetic field. It is demonstrated that a perfect spin-valley filtering effect can be obtained, where both spin and valley indices are polarized simultaneously. The spin-valley filtering benefits from the break of spatial invariance and the form of spin-valley-polarized resonant states. A high spin-valley-polarized conductance can be realized at certain values of the electric field. Furthermore, the resonant-tunneling structure composed of electric field and potential field is also feasible to fully filter spin-valley electrons, implying an electrically controlled spin-valley filter.