# Thermal photon drag in many-body systems

## TL;DR

This paper introduces a thermal analog of Coulomb drag caused by thermal photons in many-body systems, revealing effects on heat currents and potential for flow amplification, with implications for non-reciprocal systems.

## Contribution

It uncovers a new thermal drag phenomenon driven by thermal photons and explores its impact on heat currents in non-reciprocal many-body systems.

## Key findings

- Thermal photon drag can be positive or negative depending on system separation.
- Persistent heat currents at equilibrium are affected by this drag effect.
- The effect can amplify heat flows in non-reciprocal systems.

## Abstract

We demonstrate the existence of a thermal analog of Coulomb drag in many-body systems which is driven by thermal photons. We show that this frictional effect can either be positive or negative depending on the separation distances within the system. Also we highlight that the persistent heat currents flowing in non-reciprocal systems at equilibrium are subject to this effect and the latter can even amplify these flows.