{"paper":{"title":"The critical nature of the Ni spin state in doped NdNiO$_2$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.str-el"],"primary_cat":"cond-mat.supr-con","authors_text":"George A. Sawatzky, Mi Jiang, Mona Berciu","submitted_at":"2019-09-05T17:54:37Z","abstract_excerpt":"Superconductivity with $T_c \\approx 15K$ was recently found in doped NdNiO$_2$. The Ni$^{1+}$O$_2$ layers are expected to be Mott insulators so hole doping should produce Ni$^{2+}$ with $S=1$, incompatible with robust superconductivity. We show that the NiO$_2$ layers fall inside a ``critical'' region where the large $pd$ hybridization favors a singlet $^1\\!A_1$ hole-doped state like in CuO$_2$. However, we find that the superexchange is about one order smaller than in cuprates, thus a magnon ``glue'' is very unlikely and another mechanism needs to be found."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1909.02557","kind":"arxiv","version":3},"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/1909.02557/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"}