Thermodynamics of interacting systems: The role of the topology and collective effects

We study a class of system composed of interacting unicyclic machines placed in contact with a hot and cold thermal baths subjected to a nonconservative driving worksource. Despite their simplicity, these models showcase an intricate array of phenomena, including pump and heat engine regimes as well as a discontinuous phase transition. We look at three distinctive topologies: a minimal and beyond minimal (homogeneous and heterogeneous interaction structures). The former case is represented by stark different networks ("all-to-all" interactions and only a central interacting to its neighbors) and present exact solutions, whereas homogeneous and heterogeneous structures have been analyzed by numerical simulations. We find that the topology plays a major role on the thermodynamic performance for smaller values of individual energies, in part due to the presence of first-order phase transitions. Contrariwise, the topology becomes less important as individual energies increases and results are well described by a system with all-to-all interactions.