Absorption refrigerators based on Coulomb-coupled single-electron systems

TL;DR

This paper presents a theoretical analysis of a Coulomb-coupled single-electron system functioning as an absorption refrigerator, achieving Carnot efficiency and proposing experimental implementations with observable cooling power.

Contribution

It provides analytical conditions for cooling-by-heating, maximizes cooling performance, and links system parameters to measurable charge currents, advancing single-electron refrigeration technology.

Findings

System can reach Carnot's upper limit for COP.

Cooling power is measurable via charge current.

Proposed setups with quantum dots or metallic islands are experimentally feasible.

Abstract

We analyze a simple implementation of an absorption refrigerator, a system that requires heat and not work to achieve refrigeration, based on two Coulomb coupled single-electron systems. We analytically determine the general condition to achieve cooling-by-heating, and we determine the system parameters that simultaneously maximize the cooling power and cooling coefficient of performance (COP) finding that the system displays a particularly simple COP that can reach Carnot's upper limit. We also find that the cooling power can be indirectly determined by measuring a charge current. Analyzing the system as an autonomous Maxwell demon, we find that the highest efficiencies for information creation and consumption can be achieved, and we relate the COP to these efficiencies. Finally, we propose two possible experimental setups based on quantum dots or metallic islands that implement the non-trivial cooling condition. Using realistic parameters, we show that these systems, which resemble existing experimental setups, can develop an observable cooling power.