Proposal and analysis of a ferromagnetic triple-barrier resonant-tunneling spin filter

In this paper, a new type of spin filter that uses a triple-barrier structure was proposed. The proposed device consists of a non-magnetic and a ferromagnet QW. The inherent peaked I-V characteristics in the triple barrier resonant structure result in a distinct peak separation of the up-spin and the down-spin components regarding the bias voltage, which leads to an exceedingly high spin polarization. The spin dependent tunneling current and the tunnel-barrier-width dependence of both the spin polarization and the current density were theoretically calculated.