Heat rectification effect of serially coupled quantum dots

TL;DR

This paper theoretically investigates heat rectification in serially coupled quantum dots embedded in nanowires, highlighting the role of Coulomb interactions and phonon heat current in enabling directional heat flow at low temperatures.

Contribution

It introduces a theoretical model demonstrating electron heat rectification in SCQDs with significant Coulomb interactions and discusses methods to suppress phonon heat current for experimental observation.

Findings

Electron heat current exhibits direction-dependent behavior.

Phonon thermal conductivity can be reduced to observe electron heat rectification.

Heat rectification occurs in asymmetric SCQD structures at low temperatures.

Abstract

The nonlinear thermoelectric properties of serially coupled quantum dots (SCQDs) embedded in a nanowire connected to metallic electrodes are theoretically studied in the Coulomb blockade regime. We demonstrate that the electron heat current of SCQDs exhibit a direction-dependent behavior (heat rectification) in an asymmetrical structure in which the electron Coulomb interactions are significant. The phonon thermal conductivity of the nanowire is also calculated, which is used to estimate the phonon heat current. Finally, we discuss how to reduce phonon heat current to allow observation of electron heat rectification behavior in the SCQD junction system in low temperature regime ($\approx 3 K$).