Heat generation by electric current in quantum dot system responded by ac magnetic fields

摘要

We investigate the heat generation in quantum dot (QD) coupled to normal leads irradiated with a rotating magnetic field and an oscillating magnetic field by employing nonequilibrium Green's function technique. The heat generation under the influence of ac magnetic fields is very different compared with the system without perturbation of ac magnetic fields. The heat generation is suppressed by ac magnetic fields, but the changes of current is not very obvious. An ideal region for device operation is found. The threshold of source drain bias decreases due to the absorption of photons which caused by ac magnetic field. This photon absorption and emission processes also bring several mini steps in heat generation. The symmetric structure of heat generation is destroyed by the spin flip effect. As the heat generation Q is related to bessel function ~(Jn)(Λ), the heat generation displays attenuation oscillation behavior. The heat generation Q is also influenced by the linewidth function Γ.