{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b0906ccf1c881a4eaf497a262dcf105d4da5781120cea9403f20bc60145f90d8","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["b0460b1a4a3874a3dc74e099f83ba7351392ca53bfc3795b23a67ade788c04ea","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"0a12761a71657067d77853e92e3ad244037d34722935ecf48b1761c59ae70493","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.hubbard-mott.pure-model-sc","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"With only nearest-neighbor hopping, the most accurate computer methods find stripes of charge and spin instead of superconductivity, but competing states lie very close in energy.","posed_since":"1987","precise":"For the square-lattice Hubbard model with $t' = 0$, $U/t = 6\\ \\text{to}\\ 8$ and hole doping $\\delta = 1/8$, determine whether the ground state in the thermodynamic limit has long-range d-wave superconducting order or a stripe state whose pair correlations decay to zero. An answer is a controlled extrapolation of the pairing order parameter from at least two independent methods (DMRG, AFQMC, iPEPS, DMET) with consistent error bars.","problem_ref":"b0460b1a4a3874a3dc74e099f83ba7351392ca53bfc3795b23a67ade788c04ea","references":"","settled_by":"Agreement of independent unbiased methods on the extrapolated d-wave order parameter at $\\delta=1/8$ with error bars smaller than its claimed value.","status_note":"A multi-method study (2020) found filled stripes and no long-range d-wave order for $t' = 0$ at $\\delta = 1/8$; competing uniform superconducting states lie close in energy.","title":"Does the pure square-lattice Hubbard model superconduct at moderate doping?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fb9a436891c14a8b860ed1c48ae8743ee71daec594b9b75386c8c478b930cc0c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3fff69a6317d34d2f7d83566995c16e56782c129822ed5dccacab0cfffa01a03","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"HjKb3vDTS6_bWveU4T2LQubfc-cgxxRx-FakIjF3e8egaoFEQNCTBzYicvIv-qwmTuin-vpbYfFKJX2EY-E8Cw"},"schema":"pubphys.envelope/1"},"record_hash":"fb9a436891c14a8b860ed1c48ae8743ee71daec594b9b75386c8c478b930cc0c","leaf_index":2854}