Fano Effect and Spin-Polarized Transport in a Triple-Quantum-Dot Interferometer Attached to Two Ferromagnetic Leads

We report the conductance and average current through a triple-quantum-dot interferometer coupled with two ferromagnetic leads using the nonequilibrium Green's function. The results show that the interference between the resonant process and the non-resonant process leads to the formation of Fano resonance. More Fano resonances can be observed by applying a time-dependent external field. As a Zeeman magnetic field is applied, the spin-up electron transport is depressed in a certain range of electron energy levels. A spin-polarized pulse device can be realized by adjusting the spin polarization parameters of ferromagnetic leads. Moreover, the I-V characteristic curves show that under the influence of Fano resonance, the spin polarization is significantly enhanced by applying a relatively large reverse bias voltage. These results strongly suggest that the spin-polarized pulse device can be potentially applied as a spin-dependent quantum device.