Quantum Field Thermal Machines

Recent years have enjoyed an overwhelming interest in quantum thermodynamics, a field of research aimed at understanding thermodynamic tasks performed in the quantum regime. Further progress, however, seems to be obstructed by the lack of experimental implementations of thermal machines in which quantum effects play a decisive role. In this work, we introduce a blueprint of quantum field machines, which once experimentally realized would fill this gap. Even though the concept of the QFM presented here is very general and can be implemented in any many-body quantum system that can be described by a quantum field theory. We provide here a detailed proposal of how to realize a quantum machine in one-dimensional ultracold atomic gases, which consists of a set of modular operations giving rise to a piston. These can then be coupled sequentially to thermal baths, with the innovation that a quantum field takes up the role of the working fluid. In particular, we propose models for compression on the system to use it as a piston, and coupling to a bath that gives rise to a valve controlling heat flow. These models are derived within Bogoliubov theory, which allows us to study the operational primitives numerically in an efficient way. By composing the numerically modeled operational primitives we design complete quantum thermodynamic cycles that are shown to enable cooling and hence giving rise to a quantum field refrigerator. The active cooling achieved in this way can operate in regimes where existing cooling methods become ineffective. We describe the consequences of operating the machine at the quantum level and give an outlook of how this work serves as a road map to explore open questions in quantum information, quantum thermodynamic, and the study of non-Markovian quantum dynamics.

Automated summary

This study introduces a blueprint for quantum field machines, which aims to address the lack of experimental implementations of thermal machines in the quantum regime. The concept is very general and can be implemented in many-body quantum systems, with a detailed proposal for realization in one-dimensional ultracold atomic gases. Iterative numerical modeling of operational primitives leads to the design of complete quantum thermodynamic cycles capable of active cooling, showing potential in exploring open questions in quantum information and dynamics.