{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"d173ea378d3cf769452aa7cac9959140dc2a21cc9400af701829d563610d7c6f","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"9e180b5d7e2ee31d47d052e8d5711e98eaf0f86d35e26b64be3f2977cafcea93","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.nickelates.bilayer-pairing-symmetry","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"In La3Ni2O7 electrons in two nickel orbitals take part, and it is unknown whether pairs form mainly between the two layers of each bilayer or within each layer as in cuprates.","posed_since":"2023","precise":"For bilayer La3Ni2O7 (hydrostatic pressure above $\\sim 140\\,\\mathrm{kbar}$, or compressively strained films), determine the gap symmetry (interlayer $s\\pm$ between bonding and antibonding d_z2-derived bands, or d-wave dominated by d_x2-y2) and the dominant pairing interaction (interlayer superexchange of d_z2 orbitals, Hund-coupled spin fluctuations). An answer is a momentum-resolved or phase-sensitive gap measurement plus a model reproducing $T_c \\sim 80\\,\\mathrm{K}$.","problem_ref":null,"references":"","settled_by":"ARPES or quasiparticle interference on superconducting films resolving gap magnitudes and signs on each Fermi sheet, matched by a model calculation of $T_{\\mathrm{c}}$.","status_note":"Gap-symmetry measurements reported in 2025, including a d-wave claim under pressure, have not converged.","title":"Gap symmetry and pairing mechanism of bilayer La3Ni2O7","topic_ref":"1addbb7974855cb74617281e1add5f43c41622b4152f1b5d331c3da3827c5d62"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"6b2c48359751e4225d3f424a4f69791fe8adddf15f7f169702b9f95ba7aed690","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4d438338ecf3d5195108783603876c2d4952f8d633e73eb38a1cf01c10602b53","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"B9FNIsEyDhhLd3-N8q4Q98O89TedRZfT48vhqvFFu8c-3KjVhd2_nNxwhZOgUJSoV3T-g0L7bq3GDM5wCz_UAw"},"schema":"pubphys.envelope/1"},"record_hash":"6b2c48359751e4225d3f424a4f69791fe8adddf15f7f169702b9f95ba7aed690","leaf_index":1108}