Boosting the performance of small autonomous refrigerators via common environmental effects

We explore the possibility of enhancing the performance of small thermal machines by the presence
of correlated 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
established.