Thermoelectric effects in a double quantum dot system weakly coupled to ferromagnetic leads

Thermoelectric effects through a serial double quantum dot system weakly coupled to ferromagnetic leads are analyzed. Formal expressions of electrical conductance, thermal conductance, and thermal coefficient are obtained by means of Hubbard operators. The results show that although the thermopower is independent of the polarization of the leads, the figure of merit is reduced by an increase of polarization. The influences of temperature and interdot tunneling on the figure of merit are also investigated, and it is observed that increase of the interdot tunneling strength results in reduction of the figure of merit. The effect of temperature on the thermal conductance is also analyzed.

► Thermopower in a double quantum dot coupled to ferromagnetic leads is analyzed. ► Formal expressions of the thermal and electrical conductances are obtained. ► Although the thermopower is spin-independent, the figure of merit is reduced by increase of the leads’ polarization. ► Effects of temperature, interdot tunneling, and polarization on the thermoelectric characteristics of the system are also studied.