{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"a258a0f7cec7a320c81eccbeca10808f302f41089434f11060a168589b342370","created":"2026-10-03T07:18:01Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1c39273b19975c2420a9119864023e5ced5d01dd0f9e7a248e91fe2bb479c81e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.tc-limits.electronic-pairing-ceiling","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"If electron repulsion alone can make electrons pair, there should be a largest possible transition temperature, measured in units of the energy for an electron to hop between neighboring atoms; in cuprates the transition temperature is only about 3 percent of that hopping energy.","posed_since":"","precise":"For lattice models with purely repulsive interactions (Hubbard-type, bandwidth $W=8t$ on the square lattice), determine the maximum $T_c/t$ over interaction strength, filling and lattice geometry, and whether it exceeds the cuprate value $T_c/t\\sim 0.03$. An answer is controlled numerical $T_c$ values with error bars, or a bound.","problem_ref":null,"references":"","settled_by":"Unbiased finite-temperature calculations (DQMC, diagrammatic Monte Carlo, cluster methods with size extrapolation) of $T_c$ across parameter space.","status_note":"","title":"Maximum $T_c$ from purely repulsive electron interactions","topic_ref":"b4b75ff0c70cf5671429b9fb89c50704ada0cab4ee0e1be6e0ee986b669f9fe8"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"6ea2bacc6b7d9d9424329cba901d8ba9c7e1ca22e0c2fc1ecb80e6fa9c83f645","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c033cf84d36e0560254e19762afaa6b28c84a37ffcbfd7071a0817c8addc62ef","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"y7fc-ov-RfzUgqmoMar_J2r8ZIBfPdVroUArgoZ7M5Ethq_sbhq11YNjdQLnFVvj1mefL036Jase2XEhDzC_Dw"},"schema":"pubphys.envelope/1"},"record_hash":"6ea2bacc6b7d9d9424329cba901d8ba9c7e1ca22e0c2fc1ecb80e6fa9c83f645","leaf_index":1190}