Abstract
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.
- Received 1 July 2020
- Accepted 16 June 2021
DOI:https://doi.org/10.1103/PRXQuantum.2.030310
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
The field of quantum thermodynamics sets out to explore the intricate consequences of thermodynamic machines reaching dimensions so that quantum mechanics is expected to play a role. Thermodynamics is a theory of physics supposed to be set in stone, but what happens if quantum effects such as quantum correlations matter? This is one of the basic premises of the field of quantum thermodynamics, studying those effects. Despite significant progress, one can argue, however, that genuine quantum thermal machines for which one needs quantum mechanics to understand their functioning is lacking. This work not only presents a blueprint of a quantum field machine that can be seen as such a device, based on ultracold atomic quantum fields that can be manipulated in space and time. A blueprint that shows how thermodynamic cycles and machines such as Otto engines could be concretely built. But it also lays out a program that provides a vision for further study of thermodynamic machines in the quantum realm.
