{"paper":{"title":"Fermi-surface reconstruction involving two Van Hove singularities across the antiferromagnetic transition in BaFe2As2","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"A. Ino, A. Iyo, C. H. Lee, H. Anzai, H. Eisaki, H. Iwasawa, H. Namatame, H. Sato, I. Hase, K. Kihou, M. Arita, M. Taniguchi, S. Nagato, T. Oguchi, Y. Aiura, Y. Nakashima, Y. Utsumi","submitted_at":"2011-07-11T08:26:58Z","abstract_excerpt":"We report an angle-resolved photoemission study of BaFe2As2, a parent compound of iron-based superconductors. Low-energy tunable excitation photons have allowed the first observation of a saddle-point singularity at the Z point, as well as the Gamma point. With antiferromagnetic ordering, both of these two van Hove singularities come down below the Fermi energy, leading to a topological change in the innermost Fermi surface around the kz axis from cylindrical to tear-shaped, as expected from first-principles calculation. These singularities may provide an additional instability for the Fermi s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.1960","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}