Stochastic pumping of heat: Approaching the Carnot efficiency

TL;DR

This paper introduces a minimal stochastic heat pump model at the molecular scale capable of operating near Carnot efficiency by leveraging asymmetric phonon interactions and reservoir filtering.

Contribution

It presents a novel minimal model demonstrating near-Carnot efficiency in molecular heat pumping through phonon spectral filtering.

Findings

Heat pump can operate close to Carnot efficiency.

Efficiency improves with phonon filtering.

Heat pumping persists across various parameters.

Abstract

Random noise can generate a unidirectional heat current across asymmetric nano objects in the absence (or against) a temperature gradient. We present a minimal model for a molecular-level stochastic heat pump that may operate arbitrarily close to the Carnot efficiency. The model consists a fluctuating molecular unit coupled to two solids characterized by distinct phonon spectral properties. Heat pumping persists for a broad range of system and bath parameters. Furthermore, by filtering the reservoirs' phonons the pump efficiency can approach the Carnot limit.