Hybrid Thermal Machines: Generalized Thermodynamic Resources for Multitasking

TL;DR

This paper introduces hybrid thermal machines capable of multitasking by exchanging multiple conserved quantities with reservoirs, analyzing their thermodynamic limits, and demonstrating their potential in quantum dot thermoelectric setups.

Contribution

It develops a theoretical framework for hybrid thermal machines with multiple tasks and conserved quantities, and proposes a minimal model implementable in quantum dot systems.

Findings

Hybrid thermal machines can perform multiple tasks simultaneously within thermodynamic constraints.

Reservoirs with multiple conserved quantities enable enhanced machine performance.

The minimal model is feasible with realistic parameters in thermoelectric quantum dot setups.

Abstract

Thermal machines perform useful tasks--such as producing work, cooling, or heating--by exchanging energy, and possibly additional conserved quantities such as particles, with reservoirs. Here we consider thermal machines that perform more than one useful task simultaneously, terming these "hybrid thermal machines". We outline their restrictions imposed by the laws of thermodynamics and we quantify their performance in terms of efficiencies. To illustrate their full potential, reservoirs that feature multiple conserved quantities, described by generalized Gibbs ensembles, are considered. A minimal model for a hybrid thermal machine is introduced, featuring three reservoirs and two conserved quantities, e.g., energy and particle number. This model can be readily implemented in a thermoelectric setup based on quantum dots, and hybrid regimes are accessible considering realistic parameters.