{"paper":{"title":"Spin Fluctuations in the Rare-Earth Doped Bilayer Nickelates","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Rare-earth doping splits the spin fluctuation modes in bilayer nickelates and raises the interlayer coupling to 69-73 meV.","cross_cats":["cond-mat.str-el"],"primary_cat":"cond-mat.supr-con","authors_text":"Dao-Xin Yao, David Tam, Devashibhai Adroja, Gang Wang, Honglin Zhou, Huiqian Luo, Jinguang Cheng, Michael Marek Koza, Xinman Ye, Zhilun Lu","submitted_at":"2026-01-21T12:43:43Z","abstract_excerpt":"Spin fluctuations have been generally believed as the pairing glue of high-$T_c$ superconductivity. Recent inelastic neutron scattering (INS) studies have revealed a weak flat spin-fluctuation signal around 45 meV in the bilayer nickelate La$_3$Ni$_2$O$_{7-\\delta}$, suggesting strong interlayer and weak intralayer magnetic couplings ($SJ_{\\perp}\\approx$ 60 meV, $SJ_{\\parallel}\\leq$ 3.5 meV) in contrast to cuprate and pnictide superconductors. Here, we report further INS studies on the Pr and Nd doped La$_3$Ni$_2$O$_{7-\\delta}$ powder samples at ambient pressure. Besides the crystalline electri"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Our results are consistent with an enhanced interlayer coupling SJ⊥ within the stripe-type Heisenberg model framework, where the estimated SJ⊥ value is in the range of about 69 to 73 meV for the rare-earth doped bilayer nickelates.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the newly observed split modes and the 60 meV feature arise purely from enhanced interlayer exchange in a stripe Heisenberg model and are not significantly altered by doping-induced changes in crystal-field levels, disorder, or other magnetic interactions.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Rare-earth doping splits the flat 45 meV spin-fluctuation mode and adds a 60 meV feature in La3Ni2O7-δ, consistent with enhanced interlayer coupling SJ⊥ of 69–73 meV in the stripe Heisenberg model.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Rare-earth doping splits the spin fluctuation modes in bilayer nickelates and raises the interlayer coupling to 69-73 meV.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"756287b3b5b4db74c933780580017654c73719707d44ecb47a29e7a8da237e2c"},"source":{"id":"2601.14946","kind":"arxiv","version":2},"verdict":{"id":"dfcb1161-66fa-49e1-a6b3-176d15817bd3","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T12:21:14.028265Z","strongest_claim":"Our results are consistent with an enhanced interlayer coupling SJ⊥ within the stripe-type Heisenberg model framework, where the estimated SJ⊥ value is in the range of about 69 to 73 meV for the rare-earth doped bilayer nickelates.","one_line_summary":"Rare-earth doping splits the flat 45 meV spin-fluctuation mode and adds a 60 meV feature in La3Ni2O7-δ, consistent with enhanced interlayer coupling SJ⊥ of 69–73 meV in the stripe Heisenberg model.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the newly observed split modes and the 60 meV feature arise purely from enhanced interlayer exchange in a stripe Heisenberg model and are not significantly altered by doping-induced changes in crystal-field levels, disorder, or other magnetic interactions.","pith_extraction_headline":"Rare-earth doping splits the spin fluctuation modes in bilayer nickelates and raises the interlayer coupling to 69-73 meV."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2601.14946/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":2,"snapshot_sha256":"d04f82be8ba8222441fa37d385f541edeb338da20584ceb24a3518ad856bdebd"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}