{"paper":{"title":"Quantum geometry and critical temperature enhancement in MgB$_2$ superconductivity","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["cond-mat.mes-hall"],"primary_cat":"cond-mat.supr-con","authors_text":"B. Andrei Bernevig, Claudia Felser, Daniel Agterberg, Dumitru C\\u{a}lug\\u{a}ru, Emilia Morosan, Handong Chen, Hanqi Pi, Haoyu Hu, Ion Errea, Junze Deng, Kaja H. Hiorth, Leslie M. Schoop, Maia G. Vergniory, Miguel A.L. Marques, P\\\"aivi T\\\"orm\\\"a, Yi Jiang","submitted_at":"2026-07-21T18:00:00Z","abstract_excerpt":"MgB$_2$, a phonon-mediated superconductor with record-high critical temperature $T_c\\simeq 39$ K, is revisited to obtain a comprehensive theory of electrons, phonons, and their coupling with minimal ab initio input. We construct compact analytic models for the electronic structure, phonons, and electron-phonon coupling (EPC) of MgB$_2$. We show that strong in-plane B $sp^2$ bonding realizes an obstructed band structure whose natural description is a bond-centered kagome lattice, yielding small quasi-2D $\\sigma$-band Fermi-surface cylinders and pronounced quantum-geometric effects. The phonon s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.19458","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/2607.19458/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"}