{"schemaVersion":"1.0","revision":"fa961ab24277a91737c3","article":{"id":"scwiki-d3","topicId":"scwiki-topic-d3","code":"D3","slug":"cuprates","title":"Cuprates: materials, phase diagrams and open mechanisms","summary":"Separate established cuprate observations from competing pairing explanations, and attach pressure, preparation and criteria to temperature comparisons.","aliases":["copper oxide superconductors","YBCO","LSCO","Hg1223","CuO2","铜氧化物超导体","铜基超导","cuprate superconductors"],"evidenceTypes":["experiment","theory","hypothesis"],"relatedCodes":["A2","C3","C10","E1","E10","F9","G7","H2"],"editorialStatus":"scoped-check","contentState":"pilot","modifiedAt":"2026-10-19","review":{"checkedAt":"2026-10-19","scope":"Wu1987 final selected methods/results and p909 figures; Liang2005 author v1 selected doping methods/Figure1; original discovery abstracts and inherited E10 pressure-quench source checks; bounded doping/charge algebra. Follow-up: Wu p909 original page visually rechecked, Grant publication attribution, Tsuei/Hardy original abstract measurement/control distinctions, and selected Tsuei–Kirtley published review pp973–976.","limitations":["Complete scientific acceptance remains open.","Bednorz, Grant, Schilling, Gao, Tsuei and Hardy remain original-abstract checks; full methods/raw analyses are not certified.","Liang is an earlier author version; final comparison and numerical calibration reproduction remain open.","Deng selected final text/author figures do not establish independent replication, full final supplementary agreement or room-temperature stability."]},"provenance":{"repository":"JackZH26/jzis-superconductivity","commit":"0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf","path":"D_material_families/D3_cuprates.md","sha256":"2e4baff72e18764e44bd3ef4bb567e746fd92537e9709504fa7e101fba41207d","sourceId":"file-c2e5cba844537873"},"sourceMap":[{"startLine":1,"endLine":9,"targetSections":["pressure-and-recovered-samples","limits-and-disputes"],"decision":"condensed-and-structured","note":"Pressure-quench claims revisited with named E10 selected primary evidence; sample and onset criteria retained; no complete acceptance."},{"startLine":10,"endLine":15,"targetSections":["scope","limits-and-disputes"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":16,"endLine":30,"targetSections":["scope","limits-and-disputes"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":31,"endLine":36,"targetSections":["material-cases"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":37,"endLine":50,"targetSections":["scope","limits-and-disputes"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":51,"endLine":58,"targetSections":["discovery-implications"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":59,"endLine":71,"targetSections":["sources"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."},{"startLine":72,"endLine":74,"targetSections":["scope","limits-and-disputes"],"decision":"condensed-and-structured","note":"Edited English adaptation, with source-specific conditions retained. This map identifies editorial scope, not an independent verification of every original claim."}],"corrections":[{"id":"scwiki-d3-correction-1","description":"Wu1987 discovery used nominal mixed-phase Y1.2Ba0.8CuO4-y, not an independently identified pure Y123 sample; retain93K deviation/80K zero/91K magnetic criteria.","sourceId":"source-9350a30b2eabe27e","scope":"Selected final pp908–909 and p909 figures; no phase refinement."},{"id":"scwiki-d3-correction-2","description":"Remove unverified exact31GPa from the164K comparison. Selected E10 primary checks now support separately labelled pressure-quenched onset and anomaly records; supersedes the earlier complete omission.","sourceId":"source-6d09a24a26a15997","scope":"Gao abstract only; Deng E10 scope inherited, not complete acceptance."}],"equationChecks":[{"targetSectionId":"mathematical-assumptions","tex":"p=(3-2\\delta-v_c)/2","check":"Ten formal charge allocations show nonunique plane/chain partition; five two-branch empirical-dome inversion controls. No measured valence, ligand-hole density or validated doping calibration."}],"references":[{"id":"source-ad4ee05105f93caf","doi":"10.1007/BF01303701","title":"Possible high Tc superconductivity in the Ba–La–Cu–O system","year":1986,"url":"https://doi.org/10.1007/BF01303701","publicationStatus":"journal-article","verification":{"scope":"publisher-original-abstract-and-date","checkedAt":"2026-10-19","evidenceUrl":"https://link.springer.com/article/10.1007/BF01303701","note":"Publisher lists June1986. Original abstract: three-phase polycrystals, current-dependent percolative resistive onset in30K range. Full methods/figures not read: archive download406 and web screenshot returned no pixels. Do not infer a bulk magnetic transition from this abstract."}},{"id":"source-9350a30b2eabe27e","doi":"10.1103/PhysRevLett.58.908","title":"Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure","year":1987,"url":"https://doi.org/10.1103/PhysRevLett.58.908","publicationStatus":"journal-article","verification":{"scope":"selected-final-history-methods-and-figure-check","checkedAt":"2026-10-19","evidenceUrl":"https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.58.908","note":"Published2March1987. Final pp908–909 selected text and p909 Figures1–3 visually checked locally. Mixed-phase nominal Y1.2Ba0.8CuO4-y; resistive deviation93K, sharp drop92K, zero80K, diamagnetic onset91K; 24% Pb signal at4.2K is not a bulk volume fraction. Field extrapolation80–180T is not measured critical field; maximal reported applied field5.7T. No raw data or independent phase assignment."}},{"id":"source-d95477ebe515f481","doi":"10.1038/363056a0","title":"Superconductivity above 130 K in the Hg–Ba–Ca–Cu–O system","year":1993,"url":"https://doi.org/10.1038/363056a0","publicationStatus":"journal-article","verification":{"scope":"publisher-abstract-and-bibliography","checkedAt":"2026-10-18","evidenceUrl":"https://www.nature.com/articles/363056a0","note":"Published6May1993,Nature363,56–58. Original abstract magnetic/resistive context only; full methods not reviewed."}},{"id":"source-6d09a24a26a15997","doi":"10.1103/PhysRevB.50.4260","title":"Superconductivity up to 164 K in HgBa2Cam−1CumO2m+2+δ (m = 1, 2, and 3) under quasihydrostatic pressures","year":1994,"url":"https://doi.org/10.1103/PhysRevB.50.4260","publicationStatus":"journal-article","verification":{"scope":"publisher-abstract-only","checkedAt":"2026-10-18","evidenceUrl":"https://journals.aps.org/prb/abstract/10.1103/PhysRevB.50.4260","note":"Published 1 August 1994. Original abstract checked: resistive quasihydrostatic measurements up to 45 GPa and 164 K maximum for m = 3. Full PDF requires authorization; exact onset/zero criterion and point pressure not independently read."}},{"id":"source-2e4d7fdb6c1797b7","doi":"10.1103/PhysRevLett.73.593","title":"Pairing Symmetry and Flux Quantization in a Tricrystal Superconducting Ring of YBa2Cu3O7-delta","year":1994,"url":"https://doi.org/10.1103/PhysRevLett.73.593","publicationStatus":"journal-article","verification":{"scope":"publisher-original-abstract","checkedAt":"2026-10-19","evidenceUrl":"https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.73.593","note":"Original abstract: 4.2 K scanning SQUID, zero/two/three junction rings, spontaneous half flux quantum in three-junction but not two-junction rings; consistent with d-wave. Full methods, flux maps and junction controls not independently reanalyzed."}},{"id":"source-6c1991333d4a6fed","doi":"10.1038/nature14165","title":"From quantum matter to high-temperature superconductivity in copper oxides","year":2015,"url":"https://doi.org/10.1038/nature14165","publicationStatus":"journal-article","verification":{"scope":"earlier-author-manuscript-selected-passages-check","checkedAt":"2026-10-18","evidenceUrl":"https://arxiv.org/pdf/1409.4673v1","note":"Selected pp3–4 localization and competing-order context; September2014 author version precedes February2015 journal publication. No universal numerical doping or gap threshold inferred."}},{"id":"source-14d1e9e0097f7ffb","doi":"10.1073/pnas.2536178123","title":"Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench","year":2026,"url":"https://doi.org/10.1073/pnas.2536178123","publicationStatus":"journal-article","verification":{"scope":"selected-final-text-and-author-figures","checkedAt":"2026-10-18","evidenceUrl":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12993975/","note":"Final selected PMC methods/results checked; author2603.12437v1 pp9,15,21,24,25 visually checked. Online9March2026; authorv1 12March2026. Final SI comparison,rawdata and replication remain open."}},{"id":"source-e24ef58054ac9b71","doi":"10.1103/PhysRevB.73.180505","title":"Evaluation of CuO2 plane hole doping in YBa2Cu3O6+x single crystals","year":2006,"url":"https://doi.org/10.1103/PhysRevB.73.180505","publicationStatus":"journal-article","verification":{"scope":"selected-earlier-author-doping-calibration-check","checkedAt":"2026-10-19","evidenceUrl":"https://arxiv.org/pdf/cond-mat/0510674v1","note":"Author v1 submitted25October2005, related2006 journal DOI. Selected pp1–3 and p2Figure1 visually checked: oxygen ordering,1Oe c-axis field-cooled magnetic midpoint,22C diffraction and empirical calibration limitations. Publisher fulltext401; no full final comparison or fitted raw dataset reproduction."}},{"id":"source-82098193516b8d9a","doi":"10.1103/PhysRevB.35.7242","title":"Superconductivity above 90 K in the compound YBa2Cu3Ox: Structural, transport, and magnetic properties","year":1987,"url":"https://doi.org/10.1103/PhysRevB.35.7242","publicationStatus":"journal-article","verification":{"scope":"publisher-original-abstract-and-date","checkedAt":"2026-10-19","evidenceUrl":"https://journals.aps.org/prb/abstract/10.1103/PhysRevB.35.7242","note":"Published1May1987. Abstract identifies study of principal superconducting phase and structural/transport/magnetic properties. Full refinement and methods not reviewed; this separate follow-up must not be back-attributed to Wu discovery paper."}},{"id":"source-b7bc48c845a47b53","doi":"10.1103/PhysRevLett.70.3999","title":"Precision measurements of the temperature dependence of lambda in YBa2Cu3O6.95: Strong evidence for nodes in the gap function","year":1993,"url":"https://doi.org/10.1103/PhysRevLett.70.3999","publicationStatus":"journal-article","verification":{"scope":"publisher-abstract-check","checkedAt":"2026-10-19","evidenceUrl":"https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.70.3999","note":"Original abstract: 900 MHz resonator at1.3K, change in penetration depth toTc, approximately linear3–25K term. Not an absolute penetration-depth or direct gap-phase measurement. Full calibration, traces and sample comparison not reviewed."}},{"id":"source-e933e3bbd4beade6","doi":"10.1103/RevModPhys.72.969","title":"Pairing symmetry in cuprate superconductors","year":2000,"url":"https://doi.org/10.1103/RevModPhys.72.969","publicationStatus":"journal-article","verification":{"scope":"selected-review-full-text","checkedAt":"2026-10-19","evidenceUrl":"https://www.physics.umd.edu/courses/Phys798C/AnlageFall25/Kirtley%20Tsuei%20RMP.pdf","note":"Selected published review pp973–976: orthorhombic mixing, penetration depth and scattering, phase-insensitive inference limits. Conceptual context does not replace original Tsuei1994 or Hardy1993 full experimental review."}}],"materialCases":[{"formula":"HgBa2Ca2Cu3O8+delta","sample":"Hg-1223 multilayer cuprate","recordType":"experiment","tcK":133,"temperatureNote":"approximate historical reported transition; criterion not re-extracted","criterion":"unknown","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"equilibrium","probe":"discovery report","id":"scwiki-d3-material-1","sourceId":"source-d95477ebe515f481","reportedTemperatureK":133,"temperatureKind":"transition","aliases":["cuprate","cuprates"]},{"formula":"HgBa2Ca2Cu3O8+delta","sample":"quasihydrostatic high-pressure experiment","recordType":"experiment","tcK":164,"temperatureNote":"Reported maximum164K; exact point pressure and onset/zero criterion not re-extracted from original. Study maximum45GPa is not assigned to this point.","criterion":"unknown","pressureRegime":"high","pressureGPa":null,"equilibrium":"unknown","probe":"high-pressure resistance","id":"scwiki-d3-material-2","sourceId":"source-6d09a24a26a15997","reportedTemperatureK":164,"temperatureKind":"transition","aliases":["cuprate","cuprates"]},{"id":"scwiki-d3-material-3","formula":"Y1.2Ba0.8CuO4-y","sample":"Wu1987 nominal mixed-phase polycrystalline sample","recordType":"experiment","reportedTemperatureK":93,"tcK":93,"temperatureKind":"transition","temperatureNote":"Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment.","criterion":"resistive-deviation-onset","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Four-lead resistance","sourceId":"source-9350a30b2eabe27e","aliases":["Y-Ba-Cu-O discovery","cuprate","cuprates"]},{"id":"scwiki-d3-material-4","formula":"Y1.2Ba0.8CuO4-y","sample":"Wu1987 nominal mixed-phase polycrystalline sample","recordType":"experiment","reportedTemperatureK":80,"tcK":80,"temperatureKind":"transition","temperatureNote":"Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment.","criterion":"zero-resistance","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Four-lead resistance","sourceId":"source-9350a30b2eabe27e","aliases":["Y-Ba-Cu-O discovery","cuprate","cuprates"]},{"id":"scwiki-d3-material-5","formula":"Y1.2Ba0.8CuO4-y","sample":"Wu1987 nominal mixed-phase polycrystalline sample","recordType":"experiment","reportedTemperatureK":91,"tcK":91,"temperatureKind":"transition","temperatureNote":"Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment.","criterion":"magnetic-onset","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"AC inductance susceptibility","sourceId":"source-9350a30b2eabe27e","aliases":["Y-Ba-Cu-O discovery","cuprate","cuprates"]},{"id":"scwiki-d3-material-6","formula":"HgBa2Ca2Cu3O8+δ","sample":"Deng S4 experiment5; PQ18.9GPa at4.2K","recordType":"experiment","reportedTemperatureK":151,"tcK":151,"temperatureKind":"transition","temperatureNote":"Ambient onset after pressure quench; warming151.0K/cooling150.0K. Not zero resistance.","criterion":"resistive-onset","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"metastable","probe":"Resistance derivative","sourceId":"source-14d1e9e0097f7ffb","aliases":["Hg-1223","Hg1223","Deng S4"]},{"id":"scwiki-d3-material-7","formula":"HgBa2Ca2Cu3O8+δ","sample":"Deng S2 retrieved after PQ10.1GPa/4.2K","recordType":"experiment","reportedTemperatureK":140,"tcK":140,"temperatureKind":"transition","temperatureNote":"Approximate magnetic transition after retrieval; separate from S4 transport.","criterion":"magnetic-onset","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"metastable","probe":"Magnetization at10Oe","sourceId":"source-14d1e9e0097f7ffb","aliases":["Hg-1223","Hg1223","Deng S2 magnetization"]},{"id":"scwiki-d3-material-8","formula":"HgBa2Ca2Cu3O8+δ","sample":"Deng S5 after PQ29.7GPa/4.2K","recordType":"experiment","reportedTemperatureK":172,"tcK":null,"temperatureKind":"unassigned","temperatureNote":"Broad one-time anomaly not reproduced; no confirmedTc.","criterion":"unreproduced-resistive-anomaly","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Resistance on warming","sourceId":"source-14d1e9e0097f7ffb","aliases":["Hg-1223","Hg1223","Deng S5"]}],"claims":[{"id":"scwiki-d3-claim-scope-1","sectionId":"scope","statement":"Cuprates contain electronically important CuO2 planes, but layer count, oxygen coordination, charge reservoirs, disorder and doping differ across families. Many parent compounds are correlated antiferromagnetic insulators. Superconductivity, pseudogap behavior and competing orders do not define one universal phase diagram or establish a unique pairing interaction. A schematic dome organizes observations; its coordinates require a material-specific calibration.","evidenceType":"hypothesis","sourceIds":["source-6c1991333d4a6fed"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-scope-2","sectionId":"scope","statement":"The discovery sequence also needs that specificity. Bednorz and Müller's 1986 original abstract describes three-phase Ba–La–Cu–O polycrystals with a current-dependent resistivity decrease in the 30 K range, interpreted as possible percolative superconductivity. It is not a complete bulk magnetic characterization of a modern, homogeneous composition.","evidenceType":"hypothesis","sourceIds":["source-ad4ee05105f93caf"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-scope-3","sectionId":"scope","statement":"Wu and colleagues' 1987 discovery studied mixed-phase material with nominal composition Y1.2Ba0.8CuO4−y. Transport and magnetic measurements established a reproducible superconducting transition above liquid-nitrogen temperature, while powder diffraction showed multiple phases and their individual roles remained unresolved. Nominal starting composition is not an identification of the superconducting crystallographic phase. Grant and colleagues' separate paper, published on 1 May 1987, identifies YBa2Cu3Ox as the principal superconducting phase in its title and abstract; its full structural refinement has not been reviewed here. Do not retrospectively label Wu's original sample a phase-pure Y123 crystal.","evidenceType":"experiment","sourceIds":["source-9350a30b2eabe27e","source-82098193516b8d9a"],"conditions":"Nominal mixed-phase composition; transport and magnetic criteria; unresolved individual phase roles in Wu1987; Grant1987 is a separate publication.","verificationScope":"Wu final pp908–909 selected text and p909 image; Grant original title/abstract/date only; no full structural refinement or raw-data reproduction.","sourceRelationship":"context-for-editorial-analysis","derivationNote":"Wu selected final text reports mixed phases and unresolved phase roles; Grant's separate title/abstract reports the principal phase. The warning against retroactive phase-pure attribution is an editorial inference, not a new structural analysis."},{"id":"scwiki-d3-claim-mathematical-assumptions-1","sectionId":"mathematical-assumptions","statement":"Oxygen content is not automatically the hole density in a CuO2 plane. As an explicitly formal ionic exercise for YBa2Cu3O7−δ, assign Y charge +3, Ba +2, O −2, two plane Cu sites charge $2+p$, and one chain site charge $v_c$. Neutrality gives $2(2+p)+v_c=7-2\\delta$, or $p=(3-2\\delta-v_c)/2$. Ten checked allocations show that the same oxygen count admits different plane/chain charge partitions. This exercise illustrates missing information; it does not measure actual orbital occupation or include ligand-hole covalency.","evidenceType":"theory","sourceIds":["source-e24ef58054ac9b71"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.","sourceRelationship":"context-for-local-derivation","derivationNote":"Liang supplies the plane/chain calibration context; the assigned ionic charges and ten allocations are an explicitly local formal exercise, not measured orbital populations."},{"id":"scwiki-d3-claim-mathematical-assumptions-2","sectionId":"mathematical-assumptions","statement":"Liang, Bonn and Hardy's author manuscript explicitly distinguishes chain oxygen ordering from total oxygen content. Its empirical dome, $T_c/T_{c,\\max}=1-82.6(p-0.16)^2$, has two inverse branches away from its peak. Five independent algebra controls confirm that a single transition temperature cannot choose underdoping versus overdoping. The authors also discuss deviations near one-eighth doping, so treating this relation as a universal carrier-density measurement is unjustified.","evidenceType":"theory","sourceIds":["source-e24ef58054ac9b71"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.","sourceRelationship":"mixed-source-and-local-derivation","derivationNote":"Liang supplies the empirical dome and one-eighth-doping limitation; inversion branch counting and the five algebra controls are local checks, not a reproduction of the experimental calibration."},{"id":"scwiki-d3-claim-mathematical-assumptions-3","sectionId":"mathematical-assumptions","statement":"The familiar square-lattice expression $\\Delta(\\mathbf{k})\\propto\\cos k_x-\\cos k_y$ illustrates a d-wave sign structure. Its symmetry does not supply a gap magnitude, a material's exact Fermi surface or a pairing mediator. Orthorhombicity, disorder and the measurement geometry must remain part of a material-specific interpretation. See the dedicated [d-wave pairing](/scwiki/d-wave) and [gap-node](/scwiki/superconducting-node-structure) pages for the model boundaries.","evidenceType":"theory","sourceIds":["source-2e4d7fdb6c1797b7","source-6c1991333d4a6fed"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.","sourceRelationship":"context-for-editorial-analysis","derivationNote":"The lattice expression is an ideal symmetry illustration. The cited experimental and review context does not determine its amplitude, actual Fermi surface or microscopic mediator for every cuprate."},{"id":"scwiki-d3-claim-experimental-criteria-1","sectionId":"experimental-criteria","statement":"Wu's selected final text distinguishes a resistive deviation at 93 K, a sharp drop beginning at 92 K, zero resistance at 80 K and a diamagnetic onset at 91 K. The diamagnetic signal at 4.2 K was compared with a similarly sized lead sample; that relative signal is not an independently corrected superconducting volume fraction. Its 80–180 T upper-critical-field estimate is an extrapolation, whereas the reported field measurements reached 5.7 T. Preserve these criteria and scales separately.","evidenceType":"experiment","sourceIds":["source-9350a30b2eabe27e"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-experimental-criteria-2","sectionId":"experimental-criteria","statement":"A later doping-calibration experiment used a different operational criterion: Liang and colleagues chose the midpoint of the field-cooled magnetic transition with 1 Oe along the c axis. Their lattice parameter was measured by room-temperature diffraction. Temperature, field direction, oxygen ordering and the selected calibration therefore belong with the inferred doping, rather than being discarded after assigning a number to a phase diagram. Only the named author-version passages and figure have been checked here.","evidenceType":"experiment","sourceIds":["source-e24ef58054ac9b71"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-experimental-criteria-3","sectionId":"experimental-criteria","statement":"Phase-sensitive and magnitude-sensitive probes answer different questions. Tsuei and colleagues' original abstract describes scanning-SQUID measurements at 4.2 K on YBa2Cu3O7−δ rings containing zero, two or three grain-boundary junctions. It reports spontaneous half-flux-quantum magnetization, $\\Phi_0/2=h/(4e)$, in the three-junction ring but not the two-junction controls, consistent with d-wave pairing. Ring geometry and junction assumptions remain part of that inference. Hardy and colleagues' original abstract reports a 900 MHz resonator measurement of the change in penetration depth in YBa2Cu3O6.95 from 1.3 K to the transition, with an approximately linear term over 3–25 K. This is a change in penetration depth, not a direct measurement of gap phase. The Tsuei–Kirtley review distinguishes such low-energy constraints from phase-sensitive tests and discusses scattering sensitivity. Neither original abstract constitutes a check of the complete flux maps, resonator calibration or sample comparisons. Nodal evidence and pairing symmetry constrain mechanisms without selecting a unique interaction.","evidenceType":"experiment","sourceIds":["source-2e4d7fdb6c1797b7","source-b7bc48c845a47b53","source-e933e3bbd4beade6"],"conditions":"Tsuei: 4.2 K, zero/two/three grain-boundary rings, three-versus-two-junction comparison. Hardy: 900 MHz, change in penetration depth, approximately linear 3–25 K term. Junction geometry, scattering and calibration remain relevant.","verificationScope":"Original experiment abstracts only; selected Tsuei–Kirtley review Sec.II.A and symmetry context. Complete original methods, flux maps, calibration and raw-data review remain open.","sourceRelationship":"context-for-editorial-analysis","derivationNote":"Experimental numbers and controls are restricted to the original Tsuei and Hardy abstracts. The selected Tsuei–Kirtley review supplies phase-versus-magnitude and scattering context; the combined inference boundary is editorial analysis, not a full experimental reanalysis."},{"id":"scwiki-d3-claim-pressure-and-recovered-samples-1","sectionId":"pressure-and-recovered-samples","statement":"Schilling's historical Hg-based report concerns superconductivity above 130 K at ambient pressure. Gao's original abstract reports resistive measurements under quasihydrostatic pressure up to 45 GPa and a maximum of 164 K for the three-layer member. The often-quoted 31 GPa point and its onset-versus-zero criterion have not been re-extracted from the full original in this review. The comparison record therefore leaves the exact pressure unknown; a study's maximum applied pressure is not the pressure of every reported transition.","evidenceType":"experiment","sourceIds":["source-d95477ebe515f481","source-6d09a24a26a15997"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-pressure-and-recovered-samples-2","sectionId":"pressure-and-recovered-samples","statement":"The 2026 pressure-quench report now has a selected primary-text and author-figure check inherited from the [pressure-quench](/scwiki/pressure-quenching) page. Sample S4, released from 18.9 GPa at 4.2 K, showed an ambient-pressure resistive onset of 151 K on warming and 150 K on cooling. This is a reported onset in a recovered metastable sample, not a zero-resistance criterion or an equilibrium ambient-pressure phase.","evidenceType":"experiment","sourceIds":["source-14d1e9e0097f7ffb"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-pressure-and-recovered-samples-3","sectionId":"pressure-and-recovered-samples","statement":"The magnetic onset near 140 K came from retrieved sample S2, not the S4 transport sample. The estimated shielding at 70 K, the separate cold-storage protocol, and an unreproduced broad 172 K anomaly are distinct observations. The latter has no accepted transition-temperature value in this catalogue. Complete final supplementary comparison, raw-data reanalysis and independent replication remain open.","evidenceType":"experiment","sourceIds":["source-14d1e9e0097f7ffb"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-limits-and-disputes-1","sectionId":"limits-and-disputes","statement":"A charge-density modulation does not alone establish a pair-density wave; a linear resistivity does not alone determine a scattering time. Pseudogap, magnetic and charge correlations constrain theories without selecting one unique glue. Oxygen rearrangement and pressure history can alter more than carrier concentration, so a changed transition temperature does not by itself identify the causal variable. Complete scientific acceptance remains open for this article and the associated materials.","evidenceType":"hypothesis","sourceIds":["source-6c1991333d4a6fed","source-14d1e9e0097f7ffb","source-e24ef58054ac9b71"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."},{"id":"scwiki-d3-claim-discovery-implications-1","sectionId":"discovery-implications","statement":"Compare matched compositions, preparation histories and criteria. Record what each probe measures, what a model infers and what alternative explanation survives. A mechanism proposal should connect an interaction to a symmetry prediction and a falsifiable material trend. For recovered samples, add decompression temperature, storage and subsequent measurement history before comparing them with equilibrium materials. The site preserves those conditions in searchable records and section exports.","evidenceType":"hypothesis","sourceIds":["source-6c1991333d4a6fed","source-14d1e9e0097f7ffb"],"conditions":"Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.","verificationScope":"Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open."}],"body":"## Scope\n\nCuprates contain electronically important CuO2 planes, but layer count, oxygen coordination, charge reservoirs, disorder and doping differ across families. Many parent compounds are correlated antiferromagnetic insulators. Superconductivity, pseudogap behavior and competing orders do not define one universal phase diagram or establish a unique pairing interaction. A schematic dome organizes observations; its coordinates require a material-specific calibration. [R6](#ref-source-6c1991333d4a6fed)\n\nThe discovery sequence also needs that specificity. Bednorz and Müller's 1986 original abstract describes three-phase Ba–La–Cu–O polycrystals with a current-dependent resistivity decrease in the 30 K range, interpreted as possible percolative superconductivity. It is not a complete bulk magnetic characterization of a modern, homogeneous composition. [R1](#ref-source-ad4ee05105f93caf)\n\nWu and colleagues' 1987 discovery studied mixed-phase material with nominal composition Y1.2Ba0.8CuO4−y. Transport and magnetic measurements established a reproducible superconducting transition above liquid-nitrogen temperature, while powder diffraction showed multiple phases and their individual roles remained unresolved. Nominal starting composition is not an identification of the superconducting crystallographic phase. Grant and colleagues' separate paper, published on 1 May 1987, identifies YBa2Cu3Ox as the principal superconducting phase in its title and abstract; its full structural refinement has not been reviewed here. Do not retrospectively label Wu's original sample a phase-pure Y123 crystal. [R2](#ref-source-9350a30b2eabe27e) [R9](#ref-source-82098193516b8d9a)\n\n## Mathematical assumptions\n\nOxygen content is not automatically the hole density in a CuO2 plane. As an explicitly formal ionic exercise for YBa2Cu3O7−δ, assign Y charge +3, Ba +2, O −2, two plane Cu sites charge $2+p$, and one chain site charge $v_c$. Neutrality gives $2(2+p)+v_c=7-2\\delta$, or $p=(3-2\\delta-v_c)/2$. Ten checked allocations show that the same oxygen count admits different plane/chain charge partitions. This exercise illustrates missing information; it does not measure actual orbital occupation or include ligand-hole covalency. [R8](#ref-source-e24ef58054ac9b71)\n\nLiang, Bonn and Hardy's author manuscript explicitly distinguishes chain oxygen ordering from total oxygen content. Its empirical dome, $T_c/T_{c,\\max}=1-82.6(p-0.16)^2$, has two inverse branches away from its peak. Five independent algebra controls confirm that a single transition temperature cannot choose underdoping versus overdoping. The authors also discuss deviations near one-eighth doping, so treating this relation as a universal carrier-density measurement is unjustified. [R8](#ref-source-e24ef58054ac9b71)\n\nThe familiar square-lattice expression $\\Delta(\\mathbf{k})\\propto\\cos k_x-\\cos k_y$ illustrates a d-wave sign structure. Its symmetry does not supply a gap magnitude, a material's exact Fermi surface or a pairing mediator. Orthorhombicity, disorder and the measurement geometry must remain part of a material-specific interpretation. See the dedicated [d-wave pairing](/scwiki/d-wave) and [gap-node](/scwiki/superconducting-node-structure) pages for the model boundaries. [R5](#ref-source-2e4d7fdb6c1797b7) [R6](#ref-source-6c1991333d4a6fed)\n\n## Experimental criteria\n\nWu's selected final text distinguishes a resistive deviation at 93 K, a sharp drop beginning at 92 K, zero resistance at 80 K and a diamagnetic onset at 91 K. The diamagnetic signal at 4.2 K was compared with a similarly sized lead sample; that relative signal is not an independently corrected superconducting volume fraction. Its 80–180 T upper-critical-field estimate is an extrapolation, whereas the reported field measurements reached 5.7 T. Preserve these criteria and scales separately. [R2](#ref-source-9350a30b2eabe27e)\n\nA later doping-calibration experiment used a different operational criterion: Liang and colleagues chose the midpoint of the field-cooled magnetic transition with 1 Oe along the c axis. Their lattice parameter was measured by room-temperature diffraction. Temperature, field direction, oxygen ordering and the selected calibration therefore belong with the inferred doping, rather than being discarded after assigning a number to a phase diagram. Only the named author-version passages and figure have been checked here. [R8](#ref-source-e24ef58054ac9b71)\n\nPhase-sensitive and magnitude-sensitive probes answer different questions. Tsuei and colleagues' original abstract describes scanning-SQUID measurements at 4.2 K on YBa2Cu3O7−δ rings containing zero, two or three grain-boundary junctions. It reports spontaneous half-flux-quantum magnetization, $\\Phi_0/2=h/(4e)$, in the three-junction ring but not the two-junction controls, consistent with d-wave pairing. Ring geometry and junction assumptions remain part of that inference. Hardy and colleagues' original abstract reports a 900 MHz resonator measurement of the change in penetration depth in YBa2Cu3O6.95 from 1.3 K to the transition, with an approximately linear term over 3–25 K. This is a change in penetration depth, not a direct measurement of gap phase. The Tsuei–Kirtley review distinguishes such low-energy constraints from phase-sensitive tests and discusses scattering sensitivity. Neither original abstract constitutes a check of the complete flux maps, resonator calibration or sample comparisons. Nodal evidence and pairing symmetry constrain mechanisms without selecting a unique interaction. [R5](#ref-source-2e4d7fdb6c1797b7) [R10](#ref-source-b7bc48c845a47b53) [R11](#ref-source-e933e3bbd4beade6)\n\n## Pressure and recovered samples\n\nSchilling's historical Hg-based report concerns superconductivity above 130 K at ambient pressure. Gao's original abstract reports resistive measurements under quasihydrostatic pressure up to 45 GPa and a maximum of 164 K for the three-layer member. The often-quoted 31 GPa point and its onset-versus-zero criterion have not been re-extracted from the full original in this review. The comparison record therefore leaves the exact pressure unknown; a study's maximum applied pressure is not the pressure of every reported transition. [R3](#ref-source-d95477ebe515f481) [R4](#ref-source-6d09a24a26a15997)\n\nThe 2026 pressure-quench report now has a selected primary-text and author-figure check inherited from the [pressure-quench](/scwiki/pressure-quenching) page. Sample S4, released from 18.9 GPa at 4.2 K, showed an ambient-pressure resistive onset of 151 K on warming and 150 K on cooling. This is a reported onset in a recovered metastable sample, not a zero-resistance criterion or an equilibrium ambient-pressure phase. [R7](#ref-source-14d1e9e0097f7ffb)\n\nThe magnetic onset near 140 K came from retrieved sample S2, not the S4 transport sample. The estimated shielding at 70 K, the separate cold-storage protocol, and an unreproduced broad 172 K anomaly are distinct observations. The latter has no accepted transition-temperature value in this catalogue. Complete final supplementary comparison, raw-data reanalysis and independent replication remain open. [R7](#ref-source-14d1e9e0097f7ffb)\n\n## Limits and disputes\n\nA charge-density modulation does not alone establish a pair-density wave; a linear resistivity does not alone determine a scattering time. Pseudogap, magnetic and charge correlations constrain theories without selecting one unique glue. Oxygen rearrangement and pressure history can alter more than carrier concentration, so a changed transition temperature does not by itself identify the causal variable. Complete scientific acceptance remains open for this article and the associated materials. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb) [R8](#ref-source-e24ef58054ac9b71)\n\n## Discovery implications\n\nCompare matched compositions, preparation histories and criteria. Record what each probe measures, what a model infers and what alternative explanation survives. A mechanism proposal should connect an interaction to a symmetry prediction and a falsifiable material trend. For recovered samples, add decompression temperature, storage and subsequent measurement history before comparing them with equilibrium materials. The site preserves those conditions in searchable records and section exports. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb)\n\n## Related topics\n\nContinue with [magnetic evidence](/scwiki/meissner-effect), [hydrostatic pressure](/scwiki/pressure-tuning), [phase-sensitive tests](/scwiki/vortex-topological-charge), [spin-liquid and RVB proposals](/scwiki/spin-liquids-and-superconductivity), and [Planckian transport](/scwiki/planckian-dissipation).","revision":"ed0d80f8c4c63db074f0","sections":[{"id":"scope","title":"Scope","markdown":"## Scope\n\nCuprates contain electronically important CuO2 planes, but layer count, oxygen coordination, charge reservoirs, disorder and doping differ across families. Many parent compounds are correlated antiferromagnetic insulators. Superconductivity, pseudogap behavior and competing orders do not define one universal phase diagram or establish a unique pairing interaction. A schematic dome organizes observations; its coordinates require a material-specific calibration. [R6](#ref-source-6c1991333d4a6fed)\n\nThe discovery sequence also needs that specificity. Bednorz and Müller's 1986 original abstract describes three-phase Ba–La–Cu–O polycrystals with a current-dependent resistivity decrease in the 30 K range, interpreted as possible percolative superconductivity. It is not a complete bulk magnetic characterization of a modern, homogeneous composition. [R1](#ref-source-ad4ee05105f93caf)\n\nWu and colleagues' 1987 discovery studied mixed-phase material with nominal composition Y1.2Ba0.8CuO4−y. Transport and magnetic measurements established a reproducible superconducting transition above liquid-nitrogen temperature, while powder diffraction showed multiple phases and their individual roles remained unresolved. Nominal starting composition is not an identification of the superconducting crystallographic phase. Grant and colleagues' separate paper, published on 1 May 1987, identifies YBa2Cu3Ox as the principal superconducting phase in its title and abstract; its full structural refinement has not been reviewed here. Do not retrospectively label Wu's original sample a phase-pure Y123 crystal. [R2](#ref-source-9350a30b2eabe27e) [R9](#ref-source-82098193516b8d9a)"},{"id":"mathematical-assumptions","title":"Mathematical assumptions","markdown":"## Mathematical assumptions\n\nOxygen content is not automatically the hole density in a CuO2 plane. As an explicitly formal ionic exercise for YBa2Cu3O7−δ, assign Y charge +3, Ba +2, O −2, two plane Cu sites charge $2+p$, and one chain site charge $v_c$. Neutrality gives $2(2+p)+v_c=7-2\\delta$, or $p=(3-2\\delta-v_c)/2$. Ten checked allocations show that the same oxygen count admits different plane/chain charge partitions. This exercise illustrates missing information; it does not measure actual orbital occupation or include ligand-hole covalency. [R8](#ref-source-e24ef58054ac9b71)\n\nLiang, Bonn and Hardy's author manuscript explicitly distinguishes chain oxygen ordering from total oxygen content. Its empirical dome, $T_c/T_{c,\\max}=1-82.6(p-0.16)^2$, has two inverse branches away from its peak. Five independent algebra controls confirm that a single transition temperature cannot choose underdoping versus overdoping. The authors also discuss deviations near one-eighth doping, so treating this relation as a universal carrier-density measurement is unjustified. [R8](#ref-source-e24ef58054ac9b71)\n\nThe familiar square-lattice expression $\\Delta(\\mathbf{k})\\propto\\cos k_x-\\cos k_y$ illustrates a d-wave sign structure. Its symmetry does not supply a gap magnitude, a material's exact Fermi surface or a pairing mediator. Orthorhombicity, disorder and the measurement geometry must remain part of a material-specific interpretation. See the dedicated [d-wave pairing](/scwiki/d-wave) and [gap-node](/scwiki/superconducting-node-structure) pages for the model boundaries. [R5](#ref-source-2e4d7fdb6c1797b7) [R6](#ref-source-6c1991333d4a6fed)"},{"id":"experimental-criteria","title":"Experimental criteria","markdown":"## Experimental criteria\n\nWu's selected final text distinguishes a resistive deviation at 93 K, a sharp drop beginning at 92 K, zero resistance at 80 K and a diamagnetic onset at 91 K. The diamagnetic signal at 4.2 K was compared with a similarly sized lead sample; that relative signal is not an independently corrected superconducting volume fraction. Its 80–180 T upper-critical-field estimate is an extrapolation, whereas the reported field measurements reached 5.7 T. Preserve these criteria and scales separately. [R2](#ref-source-9350a30b2eabe27e)\n\nA later doping-calibration experiment used a different operational criterion: Liang and colleagues chose the midpoint of the field-cooled magnetic transition with 1 Oe along the c axis. Their lattice parameter was measured by room-temperature diffraction. Temperature, field direction, oxygen ordering and the selected calibration therefore belong with the inferred doping, rather than being discarded after assigning a number to a phase diagram. Only the named author-version passages and figure have been checked here. [R8](#ref-source-e24ef58054ac9b71)\n\nPhase-sensitive and magnitude-sensitive probes answer different questions. Tsuei and colleagues' original abstract describes scanning-SQUID measurements at 4.2 K on YBa2Cu3O7−δ rings containing zero, two or three grain-boundary junctions. It reports spontaneous half-flux-quantum magnetization, $\\Phi_0/2=h/(4e)$, in the three-junction ring but not the two-junction controls, consistent with d-wave pairing. Ring geometry and junction assumptions remain part of that inference. Hardy and colleagues' original abstract reports a 900 MHz resonator measurement of the change in penetration depth in YBa2Cu3O6.95 from 1.3 K to the transition, with an approximately linear term over 3–25 K. This is a change in penetration depth, not a direct measurement of gap phase. The Tsuei–Kirtley review distinguishes such low-energy constraints from phase-sensitive tests and discusses scattering sensitivity. Neither original abstract constitutes a check of the complete flux maps, resonator calibration or sample comparisons. Nodal evidence and pairing symmetry constrain mechanisms without selecting a unique interaction. [R5](#ref-source-2e4d7fdb6c1797b7) [R10](#ref-source-b7bc48c845a47b53) [R11](#ref-source-e933e3bbd4beade6)"},{"id":"pressure-and-recovered-samples","title":"Pressure and recovered samples","markdown":"## Pressure and recovered samples\n\nSchilling's historical Hg-based report concerns superconductivity above 130 K at ambient pressure. Gao's original abstract reports resistive measurements under quasihydrostatic pressure up to 45 GPa and a maximum of 164 K for the three-layer member. The often-quoted 31 GPa point and its onset-versus-zero criterion have not been re-extracted from the full original in this review. The comparison record therefore leaves the exact pressure unknown; a study's maximum applied pressure is not the pressure of every reported transition. [R3](#ref-source-d95477ebe515f481) [R4](#ref-source-6d09a24a26a15997)\n\nThe 2026 pressure-quench report now has a selected primary-text and author-figure check inherited from the [pressure-quench](/scwiki/pressure-quenching) page. Sample S4, released from 18.9 GPa at 4.2 K, showed an ambient-pressure resistive onset of 151 K on warming and 150 K on cooling. This is a reported onset in a recovered metastable sample, not a zero-resistance criterion or an equilibrium ambient-pressure phase. [R7](#ref-source-14d1e9e0097f7ffb)\n\nThe magnetic onset near 140 K came from retrieved sample S2, not the S4 transport sample. The estimated shielding at 70 K, the separate cold-storage protocol, and an unreproduced broad 172 K anomaly are distinct observations. The latter has no accepted transition-temperature value in this catalogue. Complete final supplementary comparison, raw-data reanalysis and independent replication remain open. [R7](#ref-source-14d1e9e0097f7ffb)"},{"id":"limits-and-disputes","title":"Limits and disputes","markdown":"## Limits and disputes\n\nA charge-density modulation does not alone establish a pair-density wave; a linear resistivity does not alone determine a scattering time. Pseudogap, magnetic and charge correlations constrain theories without selecting one unique glue. Oxygen rearrangement and pressure history can alter more than carrier concentration, so a changed transition temperature does not by itself identify the causal variable. Complete scientific acceptance remains open for this article and the associated materials. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb) [R8](#ref-source-e24ef58054ac9b71)"},{"id":"discovery-implications","title":"Discovery implications","markdown":"## Discovery implications\n\nCompare matched compositions, preparation histories and criteria. Record what each probe measures, what a model infers and what alternative explanation survives. A mechanism proposal should connect an interaction to a symmetry prediction and a falsifiable material trend. For recovered samples, add decompression temperature, storage and subsequent measurement history before comparing them with equilibrium materials. The site preserves those conditions in searchable records and section exports. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb)"},{"id":"related-topics","title":"Related topics","markdown":"## Related topics\n\nContinue with [magnetic evidence](/scwiki/meissner-effect), [hydrostatic pressure](/scwiki/pressure-tuning), [phase-sensitive tests](/scwiki/vortex-topological-charge), [spin-liquid and RVB proposals](/scwiki/spin-liquids-and-superconductivity), and [Planckian transport](/scwiki/planckian-dissipation)."},{"id":"material-cases","title":"Material cases","markdown":"## Material cases\n\nValues describe individual reports, not a ranking. Unknown means the checked source did not supply the field at this review scope.\n\n| Material and sample | Reported temperature | Criterion | Probe | Pressure | State | Evidence |\n|---|---|---|---|---|---|---|\n| HgBa2Ca2Cu3O8+delta (aliases: cuprate, cuprates); Hg-1223 multilayer cuprate | 133 K; approximate historical reported transition; criterion not re-extracted | transition; unknown | discovery report | ambient; unknown GPa | equilibrium | experiment; [source](#ref-source-d95477ebe515f481) |\n| HgBa2Ca2Cu3O8+delta (aliases: cuprate, cuprates); quasihydrostatic high-pressure experiment | 164 K; Reported maximum164K; exact point pressure and onset/zero criterion not re-extracted from original. Study maximum45GPa is not assigned to this point. | transition; unknown | high-pressure resistance | high; unknown GPa | unknown | experiment; [source](#ref-source-6d09a24a26a15997) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 93 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; resistive-deviation-onset | Four-lead resistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 80 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; zero-resistance | Four-lead resistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 91 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; magnetic-onset | AC inductance susceptibility | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S4); Deng S4 experiment5; PQ18.9GPa at4.2K | 151 K; Ambient onset after pressure quench; warming151.0K/cooling150.0K. Not zero resistance. | transition; resistive-onset | Resistance derivative | ambient; unknown GPa | metastable | experiment; [source](#ref-source-14d1e9e0097f7ffb) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S2 magnetization); Deng S2 retrieved after PQ10.1GPa/4.2K | 140 K; Approximate magnetic transition after retrieval; separate from S4 transport. | transition; magnetic-onset | Magnetization at10Oe | ambient; unknown GPa | metastable | experiment; [source](#ref-source-14d1e9e0097f7ffb) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S5); Deng S5 after PQ29.7GPa/4.2K | 172 K; Broad one-time anomaly not reproduced; no confirmedTc. | unassigned; unreproduced-resistive-anomaly | Resistance on warming | ambient; unknown GPa | unknown | experiment; [source](#ref-source-14d1e9e0097f7ffb) |"}],"markdown":"# Cuprates: materials, phase diagrams and open mechanisms\n\nSeparate established cuprate observations from competing pairing explanations, and attach pressure, preparation and criteria to temperature comparisons.\n\n## Scope\n\nCuprates contain electronically important CuO2 planes, but layer count, oxygen coordination, charge reservoirs, disorder and doping differ across families. Many parent compounds are correlated antiferromagnetic insulators. Superconductivity, pseudogap behavior and competing orders do not define one universal phase diagram or establish a unique pairing interaction. A schematic dome organizes observations; its coordinates require a material-specific calibration. [R6](#ref-source-6c1991333d4a6fed)\n\nThe discovery sequence also needs that specificity. Bednorz and Müller's 1986 original abstract describes three-phase Ba–La–Cu–O polycrystals with a current-dependent resistivity decrease in the 30 K range, interpreted as possible percolative superconductivity. It is not a complete bulk magnetic characterization of a modern, homogeneous composition. [R1](#ref-source-ad4ee05105f93caf)\n\nWu and colleagues' 1987 discovery studied mixed-phase material with nominal composition Y1.2Ba0.8CuO4−y. Transport and magnetic measurements established a reproducible superconducting transition above liquid-nitrogen temperature, while powder diffraction showed multiple phases and their individual roles remained unresolved. Nominal starting composition is not an identification of the superconducting crystallographic phase. Grant and colleagues' separate paper, published on 1 May 1987, identifies YBa2Cu3Ox as the principal superconducting phase in its title and abstract; its full structural refinement has not been reviewed here. Do not retrospectively label Wu's original sample a phase-pure Y123 crystal. [R2](#ref-source-9350a30b2eabe27e) [R9](#ref-source-82098193516b8d9a)\n\n## Mathematical assumptions\n\nOxygen content is not automatically the hole density in a CuO2 plane. As an explicitly formal ionic exercise for YBa2Cu3O7−δ, assign Y charge +3, Ba +2, O −2, two plane Cu sites charge $2+p$, and one chain site charge $v_c$. Neutrality gives $2(2+p)+v_c=7-2\\delta$, or $p=(3-2\\delta-v_c)/2$. Ten checked allocations show that the same oxygen count admits different plane/chain charge partitions. This exercise illustrates missing information; it does not measure actual orbital occupation or include ligand-hole covalency. [R8](#ref-source-e24ef58054ac9b71)\n\nLiang, Bonn and Hardy's author manuscript explicitly distinguishes chain oxygen ordering from total oxygen content. Its empirical dome, $T_c/T_{c,\\max}=1-82.6(p-0.16)^2$, has two inverse branches away from its peak. Five independent algebra controls confirm that a single transition temperature cannot choose underdoping versus overdoping. The authors also discuss deviations near one-eighth doping, so treating this relation as a universal carrier-density measurement is unjustified. [R8](#ref-source-e24ef58054ac9b71)\n\nThe familiar square-lattice expression $\\Delta(\\mathbf{k})\\propto\\cos k_x-\\cos k_y$ illustrates a d-wave sign structure. Its symmetry does not supply a gap magnitude, a material's exact Fermi surface or a pairing mediator. Orthorhombicity, disorder and the measurement geometry must remain part of a material-specific interpretation. See the dedicated [d-wave pairing](/scwiki/d-wave) and [gap-node](/scwiki/superconducting-node-structure) pages for the model boundaries. [R5](#ref-source-2e4d7fdb6c1797b7) [R6](#ref-source-6c1991333d4a6fed)\n\n## Experimental criteria\n\nWu's selected final text distinguishes a resistive deviation at 93 K, a sharp drop beginning at 92 K, zero resistance at 80 K and a diamagnetic onset at 91 K. The diamagnetic signal at 4.2 K was compared with a similarly sized lead sample; that relative signal is not an independently corrected superconducting volume fraction. Its 80–180 T upper-critical-field estimate is an extrapolation, whereas the reported field measurements reached 5.7 T. Preserve these criteria and scales separately. [R2](#ref-source-9350a30b2eabe27e)\n\nA later doping-calibration experiment used a different operational criterion: Liang and colleagues chose the midpoint of the field-cooled magnetic transition with 1 Oe along the c axis. Their lattice parameter was measured by room-temperature diffraction. Temperature, field direction, oxygen ordering and the selected calibration therefore belong with the inferred doping, rather than being discarded after assigning a number to a phase diagram. Only the named author-version passages and figure have been checked here. [R8](#ref-source-e24ef58054ac9b71)\n\nPhase-sensitive and magnitude-sensitive probes answer different questions. Tsuei and colleagues' original abstract describes scanning-SQUID measurements at 4.2 K on YBa2Cu3O7−δ rings containing zero, two or three grain-boundary junctions. It reports spontaneous half-flux-quantum magnetization, $\\Phi_0/2=h/(4e)$, in the three-junction ring but not the two-junction controls, consistent with d-wave pairing. Ring geometry and junction assumptions remain part of that inference. Hardy and colleagues' original abstract reports a 900 MHz resonator measurement of the change in penetration depth in YBa2Cu3O6.95 from 1.3 K to the transition, with an approximately linear term over 3–25 K. This is a change in penetration depth, not a direct measurement of gap phase. The Tsuei–Kirtley review distinguishes such low-energy constraints from phase-sensitive tests and discusses scattering sensitivity. Neither original abstract constitutes a check of the complete flux maps, resonator calibration or sample comparisons. Nodal evidence and pairing symmetry constrain mechanisms without selecting a unique interaction. [R5](#ref-source-2e4d7fdb6c1797b7) [R10](#ref-source-b7bc48c845a47b53) [R11](#ref-source-e933e3bbd4beade6)\n\n## Pressure and recovered samples\n\nSchilling's historical Hg-based report concerns superconductivity above 130 K at ambient pressure. Gao's original abstract reports resistive measurements under quasihydrostatic pressure up to 45 GPa and a maximum of 164 K for the three-layer member. The often-quoted 31 GPa point and its onset-versus-zero criterion have not been re-extracted from the full original in this review. The comparison record therefore leaves the exact pressure unknown; a study's maximum applied pressure is not the pressure of every reported transition. [R3](#ref-source-d95477ebe515f481) [R4](#ref-source-6d09a24a26a15997)\n\nThe 2026 pressure-quench report now has a selected primary-text and author-figure check inherited from the [pressure-quench](/scwiki/pressure-quenching) page. Sample S4, released from 18.9 GPa at 4.2 K, showed an ambient-pressure resistive onset of 151 K on warming and 150 K on cooling. This is a reported onset in a recovered metastable sample, not a zero-resistance criterion or an equilibrium ambient-pressure phase. [R7](#ref-source-14d1e9e0097f7ffb)\n\nThe magnetic onset near 140 K came from retrieved sample S2, not the S4 transport sample. The estimated shielding at 70 K, the separate cold-storage protocol, and an unreproduced broad 172 K anomaly are distinct observations. The latter has no accepted transition-temperature value in this catalogue. Complete final supplementary comparison, raw-data reanalysis and independent replication remain open. [R7](#ref-source-14d1e9e0097f7ffb)\n\n## Limits and disputes\n\nA charge-density modulation does not alone establish a pair-density wave; a linear resistivity does not alone determine a scattering time. Pseudogap, magnetic and charge correlations constrain theories without selecting one unique glue. Oxygen rearrangement and pressure history can alter more than carrier concentration, so a changed transition temperature does not by itself identify the causal variable. Complete scientific acceptance remains open for this article and the associated materials. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb) [R8](#ref-source-e24ef58054ac9b71)\n\n## Discovery implications\n\nCompare matched compositions, preparation histories and criteria. Record what each probe measures, what a model infers and what alternative explanation survives. A mechanism proposal should connect an interaction to a symmetry prediction and a falsifiable material trend. For recovered samples, add decompression temperature, storage and subsequent measurement history before comparing them with equilibrium materials. The site preserves those conditions in searchable records and section exports. [R6](#ref-source-6c1991333d4a6fed) [R7](#ref-source-14d1e9e0097f7ffb)\n\n## Related topics\n\nContinue with [magnetic evidence](/scwiki/meissner-effect), [hydrostatic pressure](/scwiki/pressure-tuning), [phase-sensitive tests](/scwiki/vortex-topological-charge), [spin-liquid and RVB proposals](/scwiki/spin-liquids-and-superconductivity), and [Planckian transport](/scwiki/planckian-dissipation).\n\n## Material cases\n\nValues describe individual reports, not a ranking. Unknown means the checked source did not supply the field at this review scope.\n\n| Material and sample | Reported temperature | Criterion | Probe | Pressure | State | Evidence |\n|---|---|---|---|---|---|---|\n| HgBa2Ca2Cu3O8+delta (aliases: cuprate, cuprates); Hg-1223 multilayer cuprate | 133 K; approximate historical reported transition; criterion not re-extracted | transition; unknown | discovery report | ambient; unknown GPa | equilibrium | experiment; [source](#ref-source-d95477ebe515f481) |\n| HgBa2Ca2Cu3O8+delta (aliases: cuprate, cuprates); quasihydrostatic high-pressure experiment | 164 K; Reported maximum164K; exact point pressure and onset/zero criterion not re-extracted from original. Study maximum45GPa is not assigned to this point. | transition; unknown | high-pressure resistance | high; unknown GPa | unknown | experiment; [source](#ref-source-6d09a24a26a15997) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 93 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; resistive-deviation-onset | Four-lead resistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 80 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; zero-resistance | Four-lead resistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| Y1.2Ba0.8CuO4-y (aliases: Y-Ba-Cu-O discovery, cuprate, cuprates); Wu1987 nominal mixed-phase polycrystalline sample | 91 K; Selected final p909; nominal mixed-phase composition, not a phase-pure Y123 assignment. | transition; magnetic-onset | AC inductance susceptibility | ambient; unknown GPa | unknown | experiment; [source](#ref-source-9350a30b2eabe27e) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S4); Deng S4 experiment5; PQ18.9GPa at4.2K | 151 K; Ambient onset after pressure quench; warming151.0K/cooling150.0K. Not zero resistance. | transition; resistive-onset | Resistance derivative | ambient; unknown GPa | metastable | experiment; [source](#ref-source-14d1e9e0097f7ffb) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S2 magnetization); Deng S2 retrieved after PQ10.1GPa/4.2K | 140 K; Approximate magnetic transition after retrieval; separate from S4 transport. | transition; magnetic-onset | Magnetization at10Oe | ambient; unknown GPa | metastable | experiment; [source](#ref-source-14d1e9e0097f7ffb) |\n| HgBa2Ca2Cu3O8+δ (aliases: Hg-1223, Hg1223, Deng S5); Deng S5 after PQ29.7GPa/4.2K | 172 K; Broad one-time anomaly not reproduced; no confirmedTc. | unassigned; unreproduced-resistive-anomaly | Resistance on warming | ambient; unknown GPa | unknown | experiment; [source](#ref-source-14d1e9e0097f7ffb) |\n\n## Sources\n\n### Ref source-ad4ee05105f93caf\n\n[R1] Possible high Tc superconductivity in the Ba–La–Cu–O system (1986). [DOI 10.1007/BF01303701](https://doi.org/10.1007/BF01303701). Publication: journal-article. Check: publisher-original-abstract-and-date. Checked: 2026-10-19. Publisher lists June1986. Original abstract: three-phase polycrystals, current-dependent percolative resistive onset in30K range. Full methods/figures not read: archive download406 and web screenshot returned no pixels. Do not infer a bulk magnetic transition from this abstract.\n### Ref source-9350a30b2eabe27e\n\n[R2] Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure (1987). [DOI 10.1103/PhysRevLett.58.908](https://doi.org/10.1103/PhysRevLett.58.908). Publication: journal-article. Check: selected-final-history-methods-and-figure-check. Checked: 2026-10-19. Published2March1987. Final pp908–909 selected text and p909 Figures1–3 visually checked locally. Mixed-phase nominal Y1.2Ba0.8CuO4-y; resistive deviation93K, sharp drop92K, zero80K, diamagnetic onset91K; 24% Pb signal at4.2K is not a bulk volume fraction. Field extrapolation80–180T is not measured critical field; maximal reported applied field5.7T. No raw data or independent phase assignment.\n### Ref source-d95477ebe515f481\n\n[R3] Superconductivity above 130 K in the Hg–Ba–Ca–Cu–O system (1993). [DOI 10.1038/363056a0](https://doi.org/10.1038/363056a0). Publication: journal-article. Check: publisher-abstract-and-bibliography. Checked: 2026-10-18. Published6May1993,Nature363,56–58. Original abstract magnetic/resistive context only; full methods not reviewed.\n### Ref source-6d09a24a26a15997\n\n[R4] Superconductivity up to 164 K in HgBa2Cam−1CumO2m+2+δ (m = 1, 2, and 3) under quasihydrostatic pressures (1994). [DOI 10.1103/PhysRevB.50.4260](https://doi.org/10.1103/PhysRevB.50.4260). Publication: journal-article. Check: publisher-abstract-only. Checked: 2026-10-18. Published 1 August 1994. Original abstract checked: resistive quasihydrostatic measurements up to 45 GPa and 164 K maximum for m = 3. Full PDF requires authorization; exact onset/zero criterion and point pressure not independently read.\n### Ref source-2e4d7fdb6c1797b7\n\n[R5] Pairing Symmetry and Flux Quantization in a Tricrystal Superconducting Ring of YBa2Cu3O7-delta (1994). [DOI 10.1103/PhysRevLett.73.593](https://doi.org/10.1103/PhysRevLett.73.593). Publication: journal-article. Check: publisher-original-abstract. Checked: 2026-10-19. Original abstract: 4.2 K scanning SQUID, zero/two/three junction rings, spontaneous half flux quantum in three-junction but not two-junction rings; consistent with d-wave. Full methods, flux maps and junction controls not independently reanalyzed.\n### Ref source-6c1991333d4a6fed\n\n[R6] From quantum matter to high-temperature superconductivity in copper oxides (2015). [DOI 10.1038/nature14165](https://doi.org/10.1038/nature14165). Publication: journal-article. Check: earlier-author-manuscript-selected-passages-check. Checked: 2026-10-18. Selected pp3–4 localization and competing-order context; September2014 author version precedes February2015 journal publication. No universal numerical doping or gap threshold inferred.\n### Ref source-14d1e9e0097f7ffb\n\n[R7] Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench (2026). [DOI 10.1073/pnas.2536178123](https://doi.org/10.1073/pnas.2536178123). Publication: journal-article. Check: selected-final-text-and-author-figures. Checked: 2026-10-18. Final selected PMC methods/results checked; author2603.12437v1 pp9,15,21,24,25 visually checked. Online9March2026; authorv1 12March2026. Final SI comparison,rawdata and replication remain open.\n### Ref source-e24ef58054ac9b71\n\n[R8] Evaluation of CuO2 plane hole doping in YBa2Cu3O6+x single crystals (2006). [DOI 10.1103/PhysRevB.73.180505](https://doi.org/10.1103/PhysRevB.73.180505). Publication: journal-article. Check: selected-earlier-author-doping-calibration-check. Checked: 2026-10-19. Author v1 submitted25October2005, related2006 journal DOI. Selected pp1–3 and p2Figure1 visually checked: oxygen ordering,1Oe c-axis field-cooled magnetic midpoint,22C diffraction and empirical calibration limitations. Publisher fulltext401; no full final comparison or fitted raw dataset reproduction.\n### Ref source-82098193516b8d9a\n\n[R9] Superconductivity above 90 K in the compound YBa2Cu3Ox: Structural, transport, and magnetic properties (1987). [DOI 10.1103/PhysRevB.35.7242](https://doi.org/10.1103/PhysRevB.35.7242). Publication: journal-article. Check: publisher-original-abstract-and-date. Checked: 2026-10-19. Published1May1987. Abstract identifies study of principal superconducting phase and structural/transport/magnetic properties. Full refinement and methods not reviewed; this separate follow-up must not be back-attributed to Wu discovery paper.\n### Ref source-b7bc48c845a47b53\n\n[R10] Precision measurements of the temperature dependence of lambda in YBa2Cu3O6.95: Strong evidence for nodes in the gap function (1993). [DOI 10.1103/PhysRevLett.70.3999](https://doi.org/10.1103/PhysRevLett.70.3999). Publication: journal-article. Check: publisher-abstract-check. Checked: 2026-10-19. Original abstract: 900 MHz resonator at1.3K, change in penetration depth toTc, approximately linear3–25K term. Not an absolute penetration-depth or direct gap-phase measurement. Full calibration, traces and sample comparison not reviewed.\n### Ref source-e933e3bbd4beade6\n\n[R11] Pairing symmetry in cuprate superconductors (2000). [DOI 10.1103/RevModPhys.72.969](https://doi.org/10.1103/RevModPhys.72.969). Publication: journal-article. Check: selected-review-full-text. Checked: 2026-10-19. Selected published review pp973–976: orthorhombic mixing, penetration depth and scattering, phase-insensitive inference limits. Conceptual context does not replace original Tsuei1994 or Hardy1993 full experimental review.\n\n## Claim evidence and conditions\n\n### scwiki-d3-claim-scope-1\n\nCuprates contain electronically important CuO2 planes, but layer count, oxygen coordination, charge reservoirs, disorder and doping differ across families. Many parent compounds are correlated antiferromagnetic insulators. Superconductivity, pseudogap behavior and competing orders do not define one universal phase diagram or establish a unique pairing interaction. A schematic dome organizes observations; its coordinates require a material-specific calibration.\n\nEvidence: hypothesis. Sources: source-6c1991333d4a6fed.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-scope-2\n\nThe discovery sequence also needs that specificity. Bednorz and Müller's 1986 original abstract describes three-phase Ba–La–Cu–O polycrystals with a current-dependent resistivity decrease in the 30 K range, interpreted as possible percolative superconductivity. It is not a complete bulk magnetic characterization of a modern, homogeneous composition.\n\nEvidence: hypothesis. Sources: source-ad4ee05105f93caf.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-scope-3\n\nWu and colleagues' 1987 discovery studied mixed-phase material with nominal composition Y1.2Ba0.8CuO4−y. Transport and magnetic measurements established a reproducible superconducting transition above liquid-nitrogen temperature, while powder diffraction showed multiple phases and their individual roles remained unresolved. Nominal starting composition is not an identification of the superconducting crystallographic phase. Grant and colleagues' separate paper, published on 1 May 1987, identifies YBa2Cu3Ox as the principal superconducting phase in its title and abstract; its full structural refinement has not been reviewed here. Do not retrospectively label Wu's original sample a phase-pure Y123 crystal.\n\nEvidence: experiment. Sources: source-9350a30b2eabe27e, source-82098193516b8d9a.\n\nSource relationship: context-for-editorial-analysis. Wu selected final text reports mixed phases and unresolved phase roles; Grant's separate title/abstract reports the principal phase. The warning against retroactive phase-pure attribution is an editorial inference, not a new structural analysis.\n\nConditions: Nominal mixed-phase composition; transport and magnetic criteria; unresolved individual phase roles in Wu1987; Grant1987 is a separate publication.\n\nVerification scope: Wu final pp908–909 selected text and p909 image; Grant original title/abstract/date only; no full structural refinement or raw-data reproduction.\n\n### scwiki-d3-claim-mathematical-assumptions-1\n\nOxygen content is not automatically the hole density in a CuO2 plane. As an explicitly formal ionic exercise for YBa2Cu3O7−δ, assign Y charge +3, Ba +2, O −2, two plane Cu sites charge $2+p$, and one chain site charge $v_c$. Neutrality gives $2(2+p)+v_c=7-2\\delta$, or $p=(3-2\\delta-v_c)/2$. Ten checked allocations show that the same oxygen count admits different plane/chain charge partitions. This exercise illustrates missing information; it does not measure actual orbital occupation or include ligand-hole covalency.\n\nEvidence: theory. Sources: source-e24ef58054ac9b71.\n\nSource relationship: context-for-local-derivation. Liang supplies the plane/chain calibration context; the assigned ionic charges and ten allocations are an explicitly local formal exercise, not measured orbital populations.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-mathematical-assumptions-2\n\nLiang, Bonn and Hardy's author manuscript explicitly distinguishes chain oxygen ordering from total oxygen content. Its empirical dome, $T_c/T_{c,\\max}=1-82.6(p-0.16)^2$, has two inverse branches away from its peak. Five independent algebra controls confirm that a single transition temperature cannot choose underdoping versus overdoping. The authors also discuss deviations near one-eighth doping, so treating this relation as a universal carrier-density measurement is unjustified.\n\nEvidence: theory. Sources: source-e24ef58054ac9b71.\n\nSource relationship: mixed-source-and-local-derivation. Liang supplies the empirical dome and one-eighth-doping limitation; inversion branch counting and the five algebra controls are local checks, not a reproduction of the experimental calibration.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-mathematical-assumptions-3\n\nThe familiar square-lattice expression $\\Delta(\\mathbf{k})\\propto\\cos k_x-\\cos k_y$ illustrates a d-wave sign structure. Its symmetry does not supply a gap magnitude, a material's exact Fermi surface or a pairing mediator. Orthorhombicity, disorder and the measurement geometry must remain part of a material-specific interpretation. See the dedicated [d-wave pairing](/scwiki/d-wave) and [gap-node](/scwiki/superconducting-node-structure) pages for the model boundaries.\n\nEvidence: theory. Sources: source-2e4d7fdb6c1797b7, source-6c1991333d4a6fed.\n\nSource relationship: context-for-editorial-analysis. The lattice expression is an ideal symmetry illustration. The cited experimental and review context does not determine its amplitude, actual Fermi surface or microscopic mediator for every cuprate.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-experimental-criteria-1\n\nWu's selected final text distinguishes a resistive deviation at 93 K, a sharp drop beginning at 92 K, zero resistance at 80 K and a diamagnetic onset at 91 K. The diamagnetic signal at 4.2 K was compared with a similarly sized lead sample; that relative signal is not an independently corrected superconducting volume fraction. Its 80–180 T upper-critical-field estimate is an extrapolation, whereas the reported field measurements reached 5.7 T. Preserve these criteria and scales separately.\n\nEvidence: experiment. Sources: source-9350a30b2eabe27e.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-experimental-criteria-2\n\nA later doping-calibration experiment used a different operational criterion: Liang and colleagues chose the midpoint of the field-cooled magnetic transition with 1 Oe along the c axis. Their lattice parameter was measured by room-temperature diffraction. Temperature, field direction, oxygen ordering and the selected calibration therefore belong with the inferred doping, rather than being discarded after assigning a number to a phase diagram. Only the named author-version passages and figure have been checked here.\n\nEvidence: experiment. Sources: source-e24ef58054ac9b71.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-experimental-criteria-3\n\nPhase-sensitive and magnitude-sensitive probes answer different questions. Tsuei and colleagues' original abstract describes scanning-SQUID measurements at 4.2 K on YBa2Cu3O7−δ rings containing zero, two or three grain-boundary junctions. It reports spontaneous half-flux-quantum magnetization, $\\Phi_0/2=h/(4e)$, in the three-junction ring but not the two-junction controls, consistent with d-wave pairing. Ring geometry and junction assumptions remain part of that inference. Hardy and colleagues' original abstract reports a 900 MHz resonator measurement of the change in penetration depth in YBa2Cu3O6.95 from 1.3 K to the transition, with an approximately linear term over 3–25 K. This is a change in penetration depth, not a direct measurement of gap phase. The Tsuei–Kirtley review distinguishes such low-energy constraints from phase-sensitive tests and discusses scattering sensitivity. Neither original abstract constitutes a check of the complete flux maps, resonator calibration or sample comparisons. Nodal evidence and pairing symmetry constrain mechanisms without selecting a unique interaction.\n\nEvidence: experiment. Sources: source-2e4d7fdb6c1797b7, source-b7bc48c845a47b53, source-e933e3bbd4beade6.\n\nSource relationship: context-for-editorial-analysis. Experimental numbers and controls are restricted to the original Tsuei and Hardy abstracts. The selected Tsuei–Kirtley review supplies phase-versus-magnitude and scattering context; the combined inference boundary is editorial analysis, not a full experimental reanalysis.\n\nConditions: Tsuei: 4.2 K, zero/two/three grain-boundary rings, three-versus-two-junction comparison. Hardy: 900 MHz, change in penetration depth, approximately linear 3–25 K term. Junction geometry, scattering and calibration remain relevant.\n\nVerification scope: Original experiment abstracts only; selected Tsuei–Kirtley review Sec.II.A and symmetry context. Complete original methods, flux maps, calibration and raw-data review remain open.\n\n### scwiki-d3-claim-pressure-and-recovered-samples-1\n\nSchilling's historical Hg-based report concerns superconductivity above 130 K at ambient pressure. Gao's original abstract reports resistive measurements under quasihydrostatic pressure up to 45 GPa and a maximum of 164 K for the three-layer member. The often-quoted 31 GPa point and its onset-versus-zero criterion have not been re-extracted from the full original in this review. The comparison record therefore leaves the exact pressure unknown; a study's maximum applied pressure is not the pressure of every reported transition.\n\nEvidence: experiment. Sources: source-d95477ebe515f481, source-6d09a24a26a15997.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-pressure-and-recovered-samples-2\n\nThe 2026 pressure-quench report now has a selected primary-text and author-figure check inherited from the [pressure-quench](/scwiki/pressure-quenching) page. Sample S4, released from 18.9 GPa at 4.2 K, showed an ambient-pressure resistive onset of 151 K on warming and 150 K on cooling. This is a reported onset in a recovered metastable sample, not a zero-resistance criterion or an equilibrium ambient-pressure phase.\n\nEvidence: experiment. Sources: source-14d1e9e0097f7ffb.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-pressure-and-recovered-samples-3\n\nThe magnetic onset near 140 K came from retrieved sample S2, not the S4 transport sample. The estimated shielding at 70 K, the separate cold-storage protocol, and an unreproduced broad 172 K anomaly are distinct observations. The latter has no accepted transition-temperature value in this catalogue. Complete final supplementary comparison, raw-data reanalysis and independent replication remain open.\n\nEvidence: experiment. Sources: source-14d1e9e0097f7ffb.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-limits-and-disputes-1\n\nA charge-density modulation does not alone establish a pair-density wave; a linear resistivity does not alone determine a scattering time. Pseudogap, magnetic and charge correlations constrain theories without selecting one unique glue. Oxygen rearrangement and pressure history can alter more than carrier concentration, so a changed transition temperature does not by itself identify the causal variable. Complete scientific acceptance remains open for this article and the associated materials.\n\nEvidence: hypothesis. Sources: source-6c1991333d4a6fed, source-14d1e9e0097f7ffb, source-e24ef58054ac9b71.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n### scwiki-d3-claim-discovery-implications-1\n\nCompare matched compositions, preparation histories and criteria. Record what each probe measures, what a model infers and what alternative explanation survives. A mechanism proposal should connect an interaction to a symmetry prediction and a falsifiable material trend. For recovered samples, add decompression temperature, storage and subsequent measurement history before comparing them with equilibrium materials. The site preserves those conditions in searchable records and section exports.\n\nEvidence: hypothesis. Sources: source-6c1991333d4a6fed, source-14d1e9e0097f7ffb.\n\nConditions: Composition, oxygen order, plane/chain allocation, probe criterion, pressure and recovered-sample history remain distinct.\n\nVerification scope: Named selected final/author passages or original abstracts, and bounded independent algebra; complete scientific acceptance open.\n\n## Revision and review\n\nArticle ID: scwiki-d3. Revision: ed0d80f8c4c63db074f0. Updated: 2026-10-19.\n\nReview scope: Wu1987 final selected methods/results and p909 figures; Liang2005 author v1 selected doping methods/Figure1; original discovery abstracts and inherited E10 pressure-quench source checks; bounded doping/charge algebra. Follow-up: Wu p909 original page visually rechecked, Grant publication attribution, Tsuei/Hardy original abstract measurement/control distinctions, and selected Tsuei–Kirtley published review pp973–976.\n\n- Complete scientific acceptance remains open.\n- Bednorz, Grant, Schilling, Gao, Tsuei and Hardy remain original-abstract checks; full methods/raw analyses are not certified.\n- Liang is an earlier author version; final comparison and numerical calibration reproduction remain open.\n- Deng selected final text/author figures do not establish independent replication, full final supplementary agreement or room-temperature stability.\n\nSource: [D_material_families/D3_cuprates.md](https://github.com/JackZH26/jzis-superconductivity/blob/0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf/D_material_families/D3_cuprates.md), commit 0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf, SHA-256 2e4baff72e18764e44bd3ef4bb567e746fd92537e9709504fa7e101fba41207d.\n","wordCount":1064}}