Thermopower Properties of Ferromagnetic/Insulator/Ferromagnetic Tunnel Junction.

The thermal conductance, thermopower, and figure of merit in the ferromagnetic/insulator/ferromagnetic tunnel junction are investigated by using the nonequilibrium Green's function technique. The magnetic regions are treated as band ferromagnetic and are described by using the single-band Hubbard model; the insulator region and the hybridization between neighboring regions are also described, respectively, by using a quantum microscopic model. It was found that the strength of the thermal conductance, the thermopower, and the figure of merit increased with the increase of the level of the left ferromagnet $$\varepsilon _{k_\mathrm{L}}$$ and the temperature $$T.$$ Finally, the calculated results of thermal properties are explained theoretically. [ABSTRACT FROM AUTHOR]