Pure spin polarized transport based on Rashba spin-orbit interaction through the Aharonov-Bohm interferometer embodied four-quantum-dot ring

摘要

The spin-polarized linear conductance spectrum and current-voltage characteristics in a four-quantum-dot ring embodied into Aharonov-Bohm (AB) interferometer are investigated theoretically by considering a local Rashba spin-orbit interaction.It shows that the spin-polarized linear conductance and the corresponding spin polarization are each a function of magnetic flux phase at zero bias voltage with a period of 2π,and that Hubbard U cannot influence the electron transport properties in this case.When adjusting appropriately the structural parameter of inter-dot coupling and dot-lead coupling strength,the electronic spin polarization can reach a maximum value.Furthermore,by adjusting the bias voltages applied to the leads,the spin-up and spin-down currents move in opposite directions and pure spin current exists in the configuration space in appropriate situations.Based on the numerical results,such a model can be applied to the design of a spin filter device.