aiqbench analysis
This research investigates the thermodynamic properties of integrable quantum systems, specifically quantifying how they deviate from standard thermal equilibrium using the concept of athermality within quantum resource theory. By analyzing various spin chains and interacting models, the study reveals singular behaviors in these deviations near critical points, offering deeper theoretical insights into non-equilibrium dynamics.
Athermality of generalized Gibbs ensembles
arXiv:2606.30762v3 Announce Type: replace-cross Abstract: Integrable quantum systems evolving from non-equilibrium initial states do not thermalize to conventional Gibbs ensembles (GE). Instead, at long times they relax to generalized Gibbs ensembles (GGEs), which incorporate the full set of local and quasi-local conserved quantities. While GGEs have been extensively studied in the literature, a quantitative analytic characterization of how different they are from ordinary GEs is still lacking. In this work, we address this question by employing the concept of athermality, which we define within quantum resource theory as the relative entropy between a given state and the closest thermal state. By means of integrability techniques we compute the athermality for several quantum quenches in paradigmatic integrable models, including the free XY spin chain, the interacting Lieb-Liniger model, the XXZ spin chain, and the harmonic chain. We find that often the athermality becomes anomalously small when the post-quench Hamiltonian is critical in its ground state, despite probing physics at a finite energy density. We also prove that it systematically develops a singularity at criticality, which is inherited from the entropy of the GGE.
Abstract:Integrable quantum systems evolving from non-equilibrium initial states do not thermalize to conventional Gibbs ensembles (GE). Instead, at long times they relax to generalized Gibbs ensembles (GGEs), which incorporate the full set of local and quasi-local conserved quantities. While GGEs have been extensively studied in the literature, a quantitative analytic characterization of how different they are from ordinary GEs is still lacking. In this work, we address this question by employing the concept of athermality, which we define within quantum resource theory as the relative entropy between a given state and the closest thermal state. By means of integrability techniques we compute the athermality for several quantum quenches in paradigmatic integrable models, including the free XY spin chain, the interacting Lieb-Liniger model, the XXZ spin chain, and the harmonic chain. We find that often the athermality becomes anomalously small when the post-quench Hamiltonian is critical in its ground state, despite probing physics at a finite energy density. We also prove that it systematically develops a singularity at criticality, which is inherited from the entropy of the GGE.
23 + 19 pages, 15 + 7 figures. Added a few references and corrected typos. Close to the final published version
Statistical Mechanics (cond-mat.stat-mech); Quantum Physics (quant-ph)
arXiv:2606.30762 [cond-mat.stat-mech]
(or arXiv:2606.30762v3 [cond-mat.stat-mech] for this version)
https://doi.org/10.48550/arXiv.2606.30762 Focus to learn more arXiv-issued DOI via DataCite
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Full text under the publisher's open licence · 293 words
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