Thermal Bias on the Pumped Spin-Current in a Two-Level Quantum Dot

Abstract

Temperature effect on the spin pump in a two-level Quantum Dot connects to Ferromagnetic and Normal leads is investigated with the help of master equation method. In addition, thermal bias, which is inevitable in practical devices, can also excite electron tunneling. Results show that the magnitude and the direction of the temperature difference between the source and drain leads have great impact on the spin current processes. By adjusting the spin pump strength, the thermal excitation currents and pumping currents can cancel each other out, thus a net spin-current without the accompany of charge-current can be obtained. In practical devices, the thermal bias is quite general and our results are helpful for the development of spintronics devices.