{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"89e214b0d281f92188c56cc713fb688aa0a06aa965dc9f82f748d2a294933042","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"74605521e6acd1b77cf0dee9a62be8f0f26333f4281b43df1ea33c2367fffc71","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.nickelates.ambient-density-wave","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"At normal pressure La3Ni2O7 does not superconduct but forms a density wave, a periodic pattern of spins and possibly charges, near 150 K; its form and its link to superconductivity are uncertain.","posed_since":"","precise":"Identify the spin and charge density-wave order of La3Ni2O7 at ambient pressure (onset near 150 K): wavevector, moment size and arrangement on the bilayer, and any charge component. Determine whether suppression of this order under pressure or strain is necessary for superconductivity. An answer is a refined magnetic structure from neutron or resonant x-ray scattering plus a phase diagram showing where the order vanishes relative to the superconducting onset.","problem_ref":null,"references":"","settled_by":"Single-crystal neutron diffraction and resonant x-ray scattering on stoichiometric crystals, followed under pressure to the superconducting regime.","status_note":"","title":"Nature of the density-wave order in ambient-pressure La3Ni2O7","topic_ref":"1addbb7974855cb74617281e1add5f43c41622b4152f1b5d331c3da3827c5d62"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bd45592b81af1645ba2059965d2e2b542120458a276a39d35cd0435a1a132288","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"61052de3248751a554944411caf131a2954c4616da348b198a1a57eab2b3b8e1","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"8yDEaBUH12zhAJktxOSPjufL98p3PXXxI9WYeCnTZgbQ3xL0krJ80g7appW6xfBif1hoJr3468nrEaKOw6xtAg"},"schema":"pubphys.envelope/1"},"record_hash":"bd45592b81af1645ba2059965d2e2b542120458a276a39d35cd0435a1a132288","leaf_index":1107}