The thermoelectric figure of merit for the single electron transistor

• We study thermoelectric transport properties of a single electron transistor.
• We model the system using the single impurity Anderson model.
• We calcule the electrical and thermal conductances and the thermopower.
• The best thermoelectric figure of merit (ZT) occurs for low hybridizations.
• The temperature interval where the best ZT occurs is T = [1 − 10] K.

We study the thermoelectric transport properties of a single electron transistor. We describe a two-level quantum dot, connected to right and left leads, employing the single impurity Anderson model with local finite electronic correlation. Using the linear response theory, we compute the thermoelectric transport coefficients. We calculate the thermoelectric properties employing the Green's functions calculated within the atomic approach, but for simplicity, we only consider the electronic contribution and neglect the phononic contribution to the thermal conductance. In the single electron transistor this is not so drastic, because the phononic contribution can be minimized, isolating the quantum dot from the electrodes with two tunneling barriers, whose material can be appropriately chosen to produce a low phononic contribution. We show that the best dimensionless thermoelectric figure of merit for the single electron transistor, occurs in the weak coupling regime, at temperatures well above the Kondo temperature.