Cooling by heating in nonequilibrium nanosystems

TL;DR

This paper reveals a counterintuitive phenomenon where increasing environmental temperature can cool nanoelectronic systems under nonequilibrium conditions, especially in molecular junctions and quantum dot systems, due to the suppression of excitation processes.

Contribution

It introduces the concept of cooling by heating in nonequilibrium nanosystems and demonstrates its robustness across various experimental parameters.

Findings

Cooling by heating occurs in nanoelectronic systems under certain conditions.

The effect is more pronounced at higher bias voltages and moderate coupling.

The phenomenon applies to systems like molecular junctions and quantum dot circuit QED.

Abstract

We demonstrate the possiblity to cool nanoelectronic systems in nonequilibrium situations by increasing the temperature of the environment. Such cooling by heating is possible for a variety of experimental conditions where the relevant transport-induced excitation processes become quenched and deexcitation processes are enhanced upon an increase of temperature. The phenomenon turns out to be robust with respect to all relevant parameters. It is especially pronounced for higher bias voltages and weak to moderate coupling. Our findings have implications for open quantum systems in general, where electron transport is coupled to mechanical (phononic) or photonic degrees of freedom. In particular, molecular junctions with rigid tunneling pathways or quantum dot circuit QED systems meet the required conditions.