{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"158daf88d91f7f3b61471240b888dab6519a51138cf2fe019c62380e85c4a9d9","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"45482c62b08e540034388874a9fba2508457b28a0ffcc5a4e487529027cdc04a","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":"1","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":null,"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":"33286b282c1fb96cb91bff4da60a136df7a46ad812b8b7d94aa4475e741e6e76"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"501aec41cc287848a12e1e135131bbd8fd813e3951209b8ec3dcd96b74c004d0","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"aa0b8b2e06509c89e872613fe3200f97550eab360dad9e0f11a3822ae6aa43aa","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"JUj38p3XsUeyTNmXeWN0AZdrkx1UB_HcHdmTI5HtCwWoNIl1gTMbkgEAjNlgyxuQ5vOC8iQUN8DFyhbdZ6LIAQ"},"schema":"pubphys.envelope/1"},"record_hash":"501aec41cc287848a12e1e135131bbd8fd813e3951209b8ec3dcd96b74c004d0","leaf_index":937}