# Quantum Synchronisation in Nanoscale Heat Engines

## TL;DR

This paper explores quantum synchronization in nanoscale heat engines, revealing its role in limiting power and efficiency, and establishing it as a key mechanism in quantum thermodynamics.

## Contribution

It demonstrates that nanoscale heat engines inherently exhibit quantum synchronization, linking phase coherence with thermodynamic performance and providing insights for quantum technology applications.

## Key findings

- Synchronization bounds the steady-state power of heat engines.
- Engine efficiency determines the temperature conditions for synchronization.
- Quantum synchronization acts as a mechanism for stable phase coherence.

## Abstract

Owing to the ubiquity of synchronization in the classical world, it is interesting to study its behavior in quantum systems. Though quantum synchronisation has been investigated in many systems, a clear connection to quantum technology applications is lacking. We bridge this gap and show that nanoscale heat engines are a natural platform to study quantum synchronization and always possess a stable limit cycle. Furthermore, we demonstrate an intimate relationship between the power of a heat engine and its phase-locking properties by proving that synchronization places an upper bound on the achievable steady-state power of the engine. Finally, we show that the efficiency of the engine sets a point in terms of the bath temperatures where synchronization vanishes. We link the physical phenomenon of synchronization with the emerging field of quantum thermodynamics by establishing quantum synchronization as a mechanism of stable phase coherence.