{ "id": "2402.04214", "version": "v1", "published": "2024-02-06T18:13:18.000Z", "updated": "2024-02-06T18:13:18.000Z", "title": "Symmetry shapes thermodynamics of macroscopic quantum systems", "authors": [ "Vasco Cavina", "Ariane Soret", "Timur Aslyamov", "Krzysztof Ptaszyński", "Massimiliano Esposito" ], "comment": "10 pages, 2 figures", "categories": [ "quant-ph", "cond-mat.stat-mech" ], "abstract": "We derive a systematic approach to the thermodynamics of quantum systems based on the underlying symmetry groups. We show that the entropy of a system can be described in terms of group-theoretical quantities that are largely independent of the details of its density matrix. We apply our technique to generic $N$ identical interacting $d$-level quantum systems. Using permutation invariance, we find that, for large $N$, entropy displays a universal large deviation behavior with a rate function $s(\\boldsymbol{x})$ that is completely independent of the microscopic details of the model, but depends only on the size of the irreducible representations of the permutation group $\\text{S}_N$. In turn, the partition function is shown to satisfy a large deviation principle with a free energy $f(\\boldsymbol{x})=e(\\boldsymbol{x})-\\beta^{-1}s(\\boldsymbol{x})$, where $e(\\boldsymbol{x})$ is a rate function that only depends on the ground state energy of particular subspaces determined by group representation theory. We apply our theory to the transverse-field Curie-Weiss model, a minimal model of phase transition exhibiting an interplay of thermal and quantum fluctuations.", "revisions": [ { "version": "v1", "updated": "2024-02-06T18:13:18.000Z" } ], "analyses": { "keywords": [ "macroscopic quantum systems", "symmetry shapes thermodynamics", "rate function", "universal large deviation behavior", "level quantum systems" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }