Spin-polarized currents through a triangle quantum dot junction driven by voltage and temperature gradient

摘要

Using the Green's function method in Hubbard model we investigate the spin-polarized currents in a triangle Quantum dot (TQD) connected to normal metal electrodes (M/TQD/M system) in the presence of Coulomb interaction. The spin-dependent currents generated by a voltage or temperature gradient in the M/TQD/M system. Results show that in both voltage-driven and temperature-driven cases the M/TQD/M system can generate spin-polarized currents with nonlinear behavior. Also, 100% current spin polarization (SP) ratio can be observed only in temperature-driven case. Besides, the spin-dependent currents and SP ratio can be interestingly controlled with the QD on-site energy, dots' level detuning factor and spin polarization factor. These results may be useful to design future spin-thermoelectric devices based on QDs.