Work Extraction Across a Thermodynamic Hierarchy in Quantum Many-Body Systems
Abstract
Thermodynamics is operational in the sense that the very concept of thermal equilibrium depends crucially on the choice of observables, while the amount of extractable work is defined relative to the allowed operations. Here we show that isolated quantum many-body states admit a thermodynamic hierarchical structure of observables and allowed operations, where the same state can be thermal at one level of the hierarchy and athermal at another. Enlarging the set of allowed operations therefore renders such hidden athermality a potential resource for work extraction; the resulting work gain is bounded in terms of the difference between the entropy densities of the two levels. This entropy difference takes the form of the mutual-information density. We establish the bounds for three extensions of operational access: increased spatial resolution, increased duration of control, and nonlocal connectivity, which provide access to position-state Holevo information, correlations between neighboring regions and spatially nonlocal correlations, respectively. Thus the difference between entropies at different levels of the thermodynamic hierarchy governs the bound on the work gain associated with moving to a less restricted level.
Related
- Thermodynamic speed limits in isolated quantum systems
- Quantum Multiscale Modeling: A Hierarchy of Algorithms for Complex Chemical Systems
- Thermodynamic Speed Limits in Isolated Quantum Systems
- Thermodynamic Uncertainty of Work in Time-Dependently Driven Open Quantum Systems
- Generalized Dunkl Quantum Systems with Energy-Dependent Interactions: Exact Solvability and Thermodynamic Properties
BibTeX
@misc{hokkyo2026work,
title = {{Work Extraction Across a Thermodynamic Hierarchy in Quantum Many-Body Systems}},
author = {Akihiro Hokkyo and Masahito Ueda},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.31001},
eprint = {2608.31001},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.31001},
}
RIS
TY - UNPB
TI - Work Extraction Across a Thermodynamic Hierarchy in Quantum Many-Body Systems
AU - Akihiro Hokkyo
AU - Masahito Ueda
PY - 2026
DA - 2026/08/31
PB - arXiv
DO - 10.48550/arxiv.2608.31001
UR - https://arxiv.org/abs/2608.31001
AB - Thermodynamics is operational in the sense that the very concept of thermal equilibrium depends crucially on the choice of observables, while the amount of extractable work is defined relative to the allowed operations. Here we show that isolated quantum many-body states admit a thermodynamic hierarchical structure of observables and allowed operations, where the same state can be thermal at one level of the hierarchy and athermal at another. Enlarging the set of allowed operations therefore renders such hidden athermality a potential resource for work extraction; the resulting work gain is bounded in terms of the difference between the entropy densities of the two levels. This entropy difference takes the form of the mutual-information density. We establish the bounds for three extensions of operational access: increased spatial resolution, increased duration of control, and nonlocal connectivity, which provide access to position-state Holevo information, correlations between neighboring regions and spatially nonlocal correlations, respectively. Thus the difference between entropies at different levels of the thermodynamic hierarchy governs the bound on the work gain associated with moving to a less restricted level.
ER -