Non-reciprocal enhancement of stochastic refrigeration

Determine whether non-reciprocity can enhance refrigeration performance, enable cooling in regimes where reciprocal systems fail, or improve the efficiency of otherwise inefficient stochastic heat engines and refrigerators, while characterizing the associated trade-offs with entropy production and coupling strength.

Background

The paper finds that non-reciprocal interactions can produce boundary refrigeration: although the total heat dissipation remains nonnegative, an individual boundary particle can absorb heat and act as an effective cold reservoir. This effect is demonstrated for the linear Ornstein–Uhlenbeck chain.

The authors leave unresolved whether the boundary-refrigeration mechanism can be used as a resource in stochastic heat engines or refrigerators, and whether it improves cooling or efficiency relative to reciprocal systems. They also identify the need to characterize the accompanying trade-offs involving entropy production and coupling strength.

References

The boundary refrigeration mechanism raises the possibility of exploiting non-reciprocity as a resource for stochastic heat engines and refrigerators. It is natural to ask whether it can enhance refrigeration performance, enable cooling where reciprocal systems fail, or improve the efficiency of otherwise inefficient stochastic machines, while characterizing the trade-offs with entropy production and coupling strength.

— Non-reciprocally interacting Ornstein-Uhlenbeck processes: Exceptional points, Anomalous relaxation, Pseudo-equilibrium and Boundary refrigeration  (2609.05391 - Pal et al., 4 Sep 2026) in Conclusion and Outlook, third bullet point