Quantum Statistical Thermal Engine at the BCS-BEC crossover
Abstract
We propose a quantum heat engine based on a two-component Fermi gas with s-wave contact interaction, operating across the BCS-BEC crossover. The work is extracted from the statistical properties of the gas, which are controlled by the interaction, rather than relying solely on compression and expansion stages. Using the functional renormalization group formalism, we obtain the equation of state in a non-perturbative form along the crossover, encompassing the superfluid-normal phase transition. The cycle combines isentropic density strokes, isochoric thermalization, and isothermal interaction sweeps. This construction makes it possible to integrate features of both Otto and Carnot cycles, in which the system simultaneously saturates both efficiency limits without the net work vanishing. In the absence of density variations, the cycle reduces to a statistical Stirling-like engine, in which the work generated arises exclusively from the interaction, achieving efficiencies up to 38%. A pronounced asymmetry emerges through the crossover, giving rise to distinct operating regimes depending on the trajectory followed in the phase diagram. Consequently, the same architecture can be tuned to function as an engine, refrigerator, accelerator, or heater. These findings highlight pairing correlations as a versatile thermodynamic resource for quantum heat machines.
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BibTeX
@misc{lira2026quantum,
title = {{Quantum Statistical Thermal Engine at the BCS-BEC crossover}},
author = {Santiago Henríquez Lira and Felipe Isaule and Martín HvE Groves and Francisco J. Peña and Patricio Vargas and Thomás Fogarty},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.37592},
eprint = {2609.37592},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.37592},
}
RIS
TY - UNPB
TI - Quantum Statistical Thermal Engine at the BCS-BEC crossover
AU - Santiago Henríquez Lira
AU - Felipe Isaule
AU - Martín HvE Groves
AU - Francisco J. Peña
AU - Patricio Vargas
AU - Thomás Fogarty
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2609.37592
UR - https://arxiv.org/abs/2609.37592
AB - We propose a quantum heat engine based on a two-component Fermi gas with s-wave contact interaction, operating across the BCS-BEC crossover. The work is extracted from the statistical properties of the gas, which are controlled by the interaction, rather than relying solely on compression and expansion stages. Using the functional renormalization group formalism, we obtain the equation of state in a non-perturbative form along the crossover, encompassing the superfluid-normal phase transition. The cycle combines isentropic density strokes, isochoric thermalization, and isothermal interaction sweeps. This construction makes it possible to integrate features of both Otto and Carnot cycles, in which the system simultaneously saturates both efficiency limits without the net work vanishing. In the absence of density variations, the cycle reduces to a statistical Stirling-like engine, in which the work generated arises exclusively from the interaction, achieving efficiencies up to 38%. A pronounced asymmetry emerges through the crossover, giving rise to distinct operating regimes depending on the trajectory followed in the phase diagram. Consequently, the same architecture can be tuned to function as an engine, refrigerator, accelerator, or heater. These findings highlight pairing correlations as a versatile thermodynamic resource for quantum heat machines.
ER -