Time-modulated near-field radiative heat transfer

TL;DR

This paper develops a formalism to analyze how time modulation affects near-field radiative heat transfer, enabling control over heat flow direction and magnitude, with potential applications in thermal diodes and heat engines.

Contribution

It introduces a rigorous fluctuational electrodynamics framework for time-modulated near-field heat transfer, revealing fundamental symmetry relations and novel control capabilities.

Findings

Time modulation can enhance, suppress, or reverse heat flow.

A radiative thermal diode with infinite contrast ratio is demonstrated.

A near-field heat engine pumping heat from cold to hot is proposed.

Abstract

We explore near-field radiative heat transfer between two bodies under time modulation by developing a rigorous fluctuational electrodynamics formalism. We demonstrate that time modulation can results in the enhancement, suppression, elimination, or reversal of radiative heat flow between the two bodies, and can be used to create a radiative thermal diode with infinite contrast ratio, as well as a near-field radiative heat engine that pumps heat from the cold to the hot bodies. The formalism reveals a fundamental symmetry relation in the radiative heat transfer coefficients that underlies these effects. Our results indicate the significant capabilities of time modulation for managing nanoscale heat flow.