Collective heat engines via different interactions: Minimal models, thermodynamics and phase transitions

TL;DR

This paper explores how different interaction types and configurations in minimal models of collective heat engines affect their thermodynamic performance, revealing regimes like heat engines and pumps, and comparing Ising, Potts, and BEG interactions.

Contribution

It introduces a comprehensive analysis of collective heat engines with various interaction topologies and types, deriving transition lines and performance regimes, and comparing different interaction models.

Findings

Potts interactions generally outperform BEG interactions.

Transition lines depend on interaction energies and contact timing.

Multiple operation regimes, including heat engine and heat pump, are identified.

Abstract

We investigate the dynamics and thermodynamics of a framework composed of interacting units in which parameters (temperatures and energies) assume distinct values due to the contact with distinct (cold and hot) thermal reservoirs. The influence of different ingredients, such as the contact between thermal baths (simultaneous versus not simultaneous contact), the coupling between them (equal or different couplings) and the topology of interactions (all-to-all and local interactions) is investigated. Closed expressions for transition lines have been obtained, expressed by a linear combination of interaction energies times reciprocal temperatures for the simultaneous thermal contact baths and deviates from it when the contact is not simultaneous. The interplay between performance and dissipation is investigated under different conditions, giving rise to a richness of operation regimes, such as heat-engine and heat pump. The relationship between thermodynamic quantities (power, efficiency and dissipation) allows a careful choice of parameters to ensure the desirable compromise between them. Finally, the influence of different interactions energies (Ising, Potts versus Blume-Emery-Griffiths (BEG) like) are investigated, revealing that Potts interactions in general present superior performances than BEG ones.