{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"454c6a5953929e0c37f30bb20867af633298d941aa88922d4c9872f57107efbe","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["52bb616da835c6b5ed2c7b2995fd1bb72e78ca25ae52034db5d55c2a3a338655","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"5102e083876f888b185f304101e952e6fa32312c746342553a02ddce864958a8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":["ai:gpt-5.5"],"external_id":"cm.cuprates.charge-transfer-tc","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"The energy needed to move an electron from oxygen to copper, the charge-transfer gap, differs between cuprate families; superexchange theories predict that a smaller gap gives stronger pairing and a higher transition temperature.","posed_since":"","precise":"For hole-doped cuprates at optimal doping, test whether $T_c,\\mathrm{max}$ and the zero-temperature pair density decrease monotonically with the charge-transfer energy $\\Delta_{\\mathrm{CT}}$ (equivalently increase with $J\\sim t_{\\mathrm{pd}}^4/\\Delta_{\\mathrm{CT}}^3$), as superexchange pairing in the three-band Emery model predicts. An answer is a cross-family data set ($\\Delta_{\\mathrm{CT}}$ from optics or tunneling, $T_c,\\mathrm{max}$, superfluid density) with a quantitative fit to model predictions, or a counterexample family.","problem_ref":"52bb616da835c6b5ed2c7b2995fd1bb72e78ca25ae52034db5d55c2a3a338655","references":"","settled_by":"Measurement of $\\Delta_{\\mathrm{CT}}$ and the pair or superfluid density in at least five cuprate families, compared with three-band model calculations of $T_{c}$ versus $\\Delta_{\\mathrm{CT}}$.","status_note":"Scanning tunneling spectroscopy on Bi2Sr2CaCu2O8+x (2022) found that the local pair density anticorrelates with the local charge-transfer gap; a cross-family quantitative test is incomplete.","title":"Does the charge-transfer gap set the maximum $T_{c}$ across cuprate families?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"48e47aabb9e316000acb4efbc9f36e535f08a2798a2ff9180de09456f1d592ba","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"036db64b7b548239c461c4ca2d06157b83e55bacf947b4f7158323c8f7c3f83b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"EcLpbxAiBVbahduuDDc8m1pWeaWbeCFiVZqs11DkH1myjOm55vhLpx3W8V5RQPKx1cIopxMd2pOa3X-8Lm7iAw"},"schema":"pubphys.envelope/1"},"record_hash":"48e47aabb9e316000acb4efbc9f36e535f08a2798a2ff9180de09456f1d592ba","leaf_index":2730}