Strongly nonlinear thermovoltage and heat dissipation in interacting quantum dots

TL;DR

This paper explores the nonlinear charge and energy transport in Coulomb-blockaded quantum dots, revealing complex thermoelectric behaviors and implications for nanoscale cooling device design.

Contribution

It uncovers the Coulomb butterfly structure in thermoelectric conductance and explains thermovoltage zeros as Coulomb resonance activations at large thermal shifts.

Findings

Coulomb butterfly structure in differential thermoelectric conductance

Thermovoltage zeros caused by Coulomb resonance activation

Power dissipation asymmetry can be voltage-controlled

Abstract

We investigate the nonlinear regime of charge and energy transport through Coulomb-blockaded quantum dots. We discuss crossed effects that arise when electrons move in response to thermal gradients (Seebeck effect) or energy flows in reaction to voltage differences (Peltier effect). We find that the differential thermoelectric conductance shows a characteristic Coulomb butterfly structure due to charging effects. Importantly, we show that experimentally observed thermovoltage zeros are caused by the activation of Coulomb resonances at large thermal shifts. Furthermore, the power dissipation asymmetry between the two attached electrodes can be manipulated with the applied voltage, which has implications for the efficient design of nanoscale coolers.