Thermoelectric current and Coulomb-blockade plateaus in a quantum dot

Author-Highlights
• Generalized Master Equation used to study thermoelectric currents in a quantum dot.
• Two semi-infinite leads with the same chemical potential but different temperatures.
• The Coulomb interaction in the sample is included via exact diagonalization.
• Current profile is saw-teeth like with alternating plateaus of almost zero current.
• Calculations go beyond the linear response with respect to the temperature gradient.

A Generalized Master Equation (GME) is used to study the thermoelectric currents through a quantum dot in both the transient and steady-state regime. The two semi-infinite leads are kept at the same chemical potential but at different temperatures to produce a thermoelectric current which has a varying sign depending on the chemical potential. The Coulomb interaction between the electrons in the sample is included via the exact diagonalization method. We observe a saw-teeth like profile of the current alternating with plateaus of almost zero current. Our calculations go beyond the linear response with respect to the temperature gradient, but are compatible with known results for the thermopower in the linear response regime.