Thermoelectric effects in a quantum dot coupled to ferromagnetic leads and subject to microwave fields

Thermoelectric properties of a quantum dot (QD) coupled to two ferromagnetic electrodes are analyzed using the Green function formalism in the linear response regime. Influence of the magnetic and microwave fields on the spin thermopower and figure of merit is investigated. Results show that the spin conductance and thermopower are strongly dependent on the spin population of the QD in the presence of the magnetic field. In addition, it is found that the magnetic field and polarization of the leads can significantly increase the spin thermopower, whereas the applying microwave field results in the increase of the fluctuation of the thermopower in low temperatures and decrease of its magnitude. It is also observed that the microwave field increases the peaks of the spin figure of merit, while the magnetic field increases its magnitude. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4800904]