{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"d5e415300acf3532967b8dfe28df47ede7d5f63bc24a23843b75228fb226f90e","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["501aec41cc287848a12e1e135131bbd8fd813e3951209b8ec3dcd96b74c004d0","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"2af218a3bcc21488be08b8f40a05dd95946d6e540b468cfd182eacb460ced8f6","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.cuprates.pdw-existence","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"A pair density wave is a superconductor whose pair amplitude oscillates in space like a standing wave; hints of it appear in tunneling maps, around magnetic vortices and in one stripe-ordered cuprate.","posed_since":"2007","precise":"Determine whether a pair-density-wave order parameter $\\Delta_Q$ with period 4 to 8 lattice constants exists as a bulk phase with long-range or quasi-long-range order at zero magnetic field in any cuprate, for example La2-xBaxCuO4 at $x = 1/8$, and whether it is a primary order or a modulation induced by coexisting charge order. An answer is a phase-sensitive or scattering detection of $\\Delta_Q$ with its correlation length, or a bound that excludes it.","problem_ref":"501aec41cc287848a12e1e135131bbd8fd813e3951209b8ec3dcd96b74c004d0","references":"","settled_by":"A bulk probe (x-ray or neutron scattering, or c-axis Josephson coupling in La2-xBaxCuO4) showing long-range $\\Delta_Q$ order with a correlation length exceeding that of the coexisting charge order.","status_note":"Scanned Josephson tunneling found a $4a0$ pair-density modulation in Bi2Sr2CaCu2O8+x at zero field (2016) and field-induced $8a0$ modulations near vortex cores (2019); whether a primary long-range pair density wave exists in the bulk is not established.","title":"Is there a bulk pair density wave in any cuprate?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"00db4275e8cb111caae728af7392b61bedbcf1766792c4f05baddee452eb151a","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3fc66c404756e1f1da569377aced594fd865c90d55df0e8861fa5c1ef99d109d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"nutpUSOPVz9q2kaFTixNkbg1gP-5cKUTUgd_a-B9WOJ4BGOXQmr0VbMnqerB1UkPMh_Nb0Fw93xCqVdza7d9Ag"},"schema":"pubphys.envelope/1"},"record_hash":"00db4275e8cb111caae728af7392b61bedbcf1766792c4f05baddee452eb151a","leaf_index":2736}