Thermoelectric effects in transport through quantum dots attached to ferromagnetic leads with noncollinear magnetic moments

Charge transport accompanied by heat transfer through a single-level quantum dot coupled to ferromagnetic leads with noncollinear magnetic moments is studied theoretically in the linear and nonlinear transport regimes. Calculations performed in the framework of nonequilibrium Green's function formalism and the equation of motion method reveal a significant influence of Coulomb blockade on thermal transport processes. The thermopower S and thermal efficiency described by the figure of merit ZT depend on magnetic configuration of the system. Two physically different situations are considered; one appears when spin accumulation is excluded and the second one when spin accumulation is relevant. In the latter case we also calculate the corresponding spin thermopower. Apart from this, magnetothermopower is introduced and discussed.