Boosting the performance of small autonomous refrigerators via common environmental effects

TL;DR

This paper demonstrates that common environmental noise can significantly improve the performance of small autonomous quantum refrigerators, nearly doubling cooling power without efficiency loss, especially when leveraging decoherence-free subspaces.

Contribution

It introduces a method to enhance quantum refrigerator performance by engineering common reservoir couplings, highlighting the role of decoherence-free subspaces and correlated dissipation effects.

Findings

Performance nearly doubled with common environment engineering.

Decoherence-free subspaces lead to significant improvements.

Correlated dissipation effects influence refrigerator efficiency.

Abstract

We explore the possibility of enhancing the performance of small thermal machines by the presence of common noise sources. In particular, we study a prototypical model for an autonomous quantum refrigerator comprised by three qubits coupled to thermal reservoirs at different temperatures. Our results show that engineering the coupling to the reservoirs to act as common environments lead to relevant improvements in the performance. The enhancements arrive to almost double the cooling power of the original fridge without compromising its efficiency. The greater enhancements are obtained when the refrigerator may benefit from the presence of a decoherence-free subspace. The influence of coherent effects in the dissipation due to one- and two-spin correlated processes is also examined by comparison with an equivalent incoherent yet correlated model of dissipation.