{"paper":{"title":"Thermodynamics in a split Hilbert space: Quantum impurity at the edge of the Heisenberg chain","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["hep-th","math-ph","math.MP","nlin.SI","quant-ph"],"primary_cat":"cond-mat.str-el","authors_text":"Abay Zhakenov, Natan Andrei, Pradip Kattel","submitted_at":"2025-08-26T18:00:02Z","abstract_excerpt":"We study the isotropic spin-$\\frac{1}{2}$ Heisenberg chain with a single edge-coupled impurity of arbitrary exchange strength $J$. The model exhibits four impurity phases. For antiferromagnetic couplings ($J>0$): a \\textit{Kondo phase} at weak $J$, where the impurity is screened by many-body excitations and the impurity entropy decreases monotonically from $\\ln 2$ at $T \\to \\infty$ to $0$ at $T\\to 0$; and an \\textit{antiferromagnetic bound-mode (ABM) phase} at strong $J$, where the impurity screened by an exponentially localized bound mode drives $S_{\\mathrm{imp}}(T)$ nonmonotonically, with un"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2508.19334","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2508.19334/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}