{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0c1e00869271c742bd63aaadd2d6d09ebd305e69d81a30412e4d18d7132a61c7","created":"2026-10-03T07:18:01Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"a685c7972c66454912009c3d6fba4b0550da420b2523e319881476c5e538965f","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.strange-metals.planckian-universality","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Data in several materials suggest the electron scattering rate equals temperature times a fixed combination of Boltzmann's and Planck's constants; it is unknown whether this is a true limit.","posed_since":"2004","precise":"With $\\hbar/\\tau = \\alpha k_B T$ extracted from the T-linear resistivity slope and the independently measured effective mass and carrier density, test whether $\\alpha = 1$ within error across strange metals and whether any metal sustains $\\alpha >> 1$. An answer is a proof of a bound on the transport scattering rate within a defined class of models, or a material with reliably measured $\\alpha$ well above 1.","problem_ref":null,"references":"","settled_by":"Quantum-oscillation or specific-heat masses combined with resistivity slopes in many materials, plus a theorem bounding $\\hbar/\\tau$ in a stated class of models.","status_note":"Analyses of several hole-doped cuprates (2019) gave $\\alpha \\sim 1$; no rigorous bound on the transport rate is known.","title":"Is the Planckian scattering rate universal, and is it a bound","topic_ref":"bfd78216bee7da77225ac2973e7d9a78ff7a1c51ad977d9d7c3327e70d7ac174"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d887532c1f6edd1e8747472a7d74fa9c48c33c7fed4ce231740d5f992602181a","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8ff56379c80425206cca13917da934e266f0ca68a3d82252d3f58bb17b6210cf","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"BTEjNgQv_m3jzFnXcnK5iQfQSv3SVSgF1BT7I7odY0Pyz9zYlTmnKeoMaVj60_hdBUauMcLkc87D-WyUsstYCw"},"schema":"pubphys.envelope/1"},"record_hash":"d887532c1f6edd1e8747472a7d74fa9c48c33c7fed4ce231740d5f992602181a","leaf_index":1178}