{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e0a52e82fa31b538041f6148d7e96d0d7d1b788a0d9275e469d1d137d65a4a57","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["bd45592b81af1645ba2059965d2e2b542120458a276a39d35cd0435a1a132288","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"4e9b221dc64590d9dfb0625dbd5708bbcf85deeccd4deec477275ae05eb1774e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":["ai:gpt-5.5"],"external_id":"cm.nickelates.ambient-density-wave","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"At normal pressure $\\mathrm{La_3Ni_2O_7}$ does not superconduct but forms a density wave, a periodic pattern of spins and possibly charges, near $150\\ \\mathrm{K}$; its form and its link to superconductivity are uncertain.","posed_since":"","precise":"Identify the spin and charge density-wave order of $\\mathrm{La_3Ni_2O_7}$ at ambient pressure (onset near $150\\ \\mathrm{K}$): 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":"bd45592b81af1645ba2059965d2e2b542120458a276a39d35cd0435a1a132288","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 $\\mathrm{La_3Ni_2O_7}$","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bfca129cc273e86b6122d690a7ca41cd6dd9beb1c1286e80327d7fe1eb68a407","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"35e3c600a2481ffae2c35dbcff224d054e1fbcd2a25bb6d336e6702b48c8e4de","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"rtAr2GcRykFGvqIlkZmkg4vprhp4haqUzF4rcJdIQniYIg0tva7DjqsR-wikpTaQlJNVLhXjOhny71BJaflGCA"},"schema":"pubphys.envelope/1"},"record_hash":"bfca129cc273e86b6122d690a7ca41cd6dd9beb1c1286e80327d7fe1eb68a407","leaf_index":2964}