The cooling effect in an InAs quantum dot subjected to THz irradiation and an external magnetic field

Using the non-equilibrium Green's function method, we theoretically investigate the thermoelectric transport properties in an InAs quantum dot subjected to THz irradiation and an external magnetic field. Very interestingly, we get the cooling effect under the asymmetric THz irradiation, i.e., the heat current shows a negative value through particular photon-assisted tunneling channels, and we can switch the direction of heat current effectively just by changing both the THz frequency and the gate voltage. In addition, when a THz field is applied to two leads symmetrically, we reveal the dependence of the charge and spin figure of merit on the temperature in various magnetic fields. It is found that the spin figure of merit is sensitive to the magnetic field. These results shed some light on potential applications of the cooling effect in controlling the heat current from THz irradiation.