{"schemaVersion":"1.0","revision":"fa961ab24277a91737c3","article":{"id":"scwiki-h2","topicId":"scwiki-topic-h2","code":"H2","slug":"planckian-dissipation","title":"Planckian dissipation: definitions and inference","summary":"A linear resistivity does not by itself measure a Planckian lifetime. Specify the relaxation channel, residual rate, frequency convention and transport model.","aliases":["Planckian dissipation","Planckian limit","scattering time","Drude","普朗克耗散","普朗克极限"],"evidenceTypes":["experiment","theory","hypothesis"],"relatedCodes":["H1","A8","D4"],"editorialStatus":"scoped-check","contentState":"pilot","modifiedAt":"2026-10-18T16:34:01.759993+00:00","review":{"checkedAt":"2026-10-19","scope":"Selected Bruin opening page, Legros author scaling passages, inherited final Nd-LSCO and author FeTeSe figure checks, conditional chaos theorem passages and independent lifetime-model checks.","limitations":["Complete scientific acceptance remains open.","Bruin pages805–807 and supplementary tables were not retrieved in the selected PDF.","Legros and Romero final-version comparison, fitting covariance and raw-data reproduction remain incomplete.","Elastic event-model and residual-rate checks do not establish universal transport or chaos bounds."]},"provenance":{"repository":"JackZH26/jzis-superconductivity","commit":"0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf","path":"H_anomalous_normal_state/H2_Planckian_limit.md","sha256":"25c50026c1a52dd82561048516dabc03c0ecee3dba8044d90552cea0fdb59f28","sourceId":"file-53ac5f5ad318565e"},"sourceMap":[{"startLine":1,"endLine":9,"targetSections":["mathematical-assumptions"],"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":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":33,"targetSections":["mathematical-assumptions"],"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":34,"endLine":56,"targetSections":["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":57,"endLine":89,"targetSections":["experimental-criteria"],"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":90,"endLine":105,"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":106,"endLine":117,"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":118,"endLine":132,"targetSections":["experimental-criteria"],"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":133,"endLine":144,"targetSections":[],"decision":"not-published-as-scientific-evidence","note":"Historical audit scores and repeated summaries are not scientific verification. Selected cautions are rewritten in the limits section."},{"startLine":145,"endLine":155,"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":156,"endLine":161,"targetSections":[],"decision":"not-published-as-scientific-evidence","note":"Historical audit scores and repeated summaries are not scientific verification. Selected cautions are rewritten in the limits section."}],"corrections":[{"id":"scwiki-h2-correction-1","description":"The converted formula distinguishes total alpha(T) from a residual-subtracted inelastic slope. A nonzero residual rate cannot be silently included in a temperature-independent Planckian coefficient.","sourceId":"source-67da95cac5481029","scope":"Notation and dimensions; no new fitted alpha values."},{"id":"scwiki-h2-correction-2","description":"Reclassified the chaos-bound claim as theory, made its assumptions explicit, and removed experiment labels from conceptual guidance. Primary-source passage checks are scoped and do not validate the empirical references.","sourceId":"source-8339743a9f1c3239","scope":"Evidence classification and conditional chaos/transport distinction."},{"id":"scwiki-h2-correction-3","description":"Experimental source scopes now identify retrieved pages and author versions; the Drude cycle-frequency coefficient is converted consistently to an angular decay rate.","sourceId":"source-05b2d5ff6757b5eb","scope":"Lifetime and version conventions; no final raw-data replication claimed."}],"equationChecks":[{"targetSectionId":"mathematical-assumptions","tex":"\\gamma_{\\mathrm{tr}}=\\gamma(1-a/2)","check":"15 independent numerical angular-kernel integrations; defined elastic event convention, not a spectral half-width."},{"targetSectionId":"mathematical-assumptions","tex":"\\alpha_{\\mathrm{tot}}=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)","check":"27 independent residual-rate ratios; additivity is an assumption, not a material result."},{"targetSectionId":"limits-and-disputes","tex":"\\lambda_L\\leq2\\pi k_BT/\\hbar","check":"Inherited published MSS Eq.(2.5) scoped check; no identification with transport and no independent proof verification."}],"references":[{"id":"source-67da95cac5481029","doi":"10.1103/RevModPhys.94.041002","title":"Colloquium: Planckian dissipation in metals","year":2022,"url":"https://doi.org/10.1103/RevModPhys.94.041002","publicationStatus":"journal-article","verification":{"scope":"review-full-text-scoped-check","checkedAt":"2026-10-18","evidenceUrl":"https://arxiv.org/html/2107.07802v3","note":"Author manuscript v3 (18 June 2022), sections 1.4, 4, 4.1 and 5, Eqs. (28)-(32): residual subtraction, distinct lifetimes, effective-mass/vertex caveats, and chaos versus transport. This review-level check does not verify the underlying experiments or every statement in H2."}},{"id":"source-e6d342432f3409ae","doi":"10.1126/science.1227612","title":"Similarity of Scattering Rates in Metals Showing T-Linear Resistivity","year":2013,"url":"https://doi.org/10.1126/science.1227612","publicationStatus":"journal-article","verification":{"scope":"selected-final-opening-page-check","checkedAt":"2026-10-19","evidenceUrl":"https://lab.semi.ac.cn/download/0.4390469575788667.pdf","note":"Printed page 804 (PDF page 5) read and visually checked: abstract and opening discussion. This download mostly contains an adjacent article and does not include pages 805–807. Figure fits and supplementary parameter tables remain unaudited. Author institutional record confirms 15 February 2013."}},{"id":"source-c1ae7869b672a8e8","doi":"10.1038/s41567-018-0334-2","title":"Universal T-linear resistivity and Planckian dissipation in overdoped cuprates","year":2019,"url":"https://doi.org/10.1038/s41567-018-0334-2","publicationStatus":"journal-article","verification":{"scope":"earlier-author-manuscript-scoped-check","checkedAt":"2026-10-18","evidenceUrl":"https://arxiv.org/pdf/1805.02512v1","note":"Selected v1 pp. 4, 7–8 and Figs. 1–2 captions: Drude assumptions, film method and magnetoresistance correction. Published volume year 2019; final-version comparison and complete data fitting remain open. H2 additionally checked v1 pp.4–5, Eq.(1), mass estimates and uncertainty discussion. Final PDF attempts were unavailable; no final full-text comparison is claimed."}},{"id":"source-05b2d5ff6757b5eb","doi":"10.1038/s41567-026-03266-8","title":"Planckian scattering and parallel conduction channels in an iron chalcogenide superconductor","year":2026,"url":"https://doi.org/10.1038/s41567-026-03266-8","publicationStatus":"journal-article","verification":{"scope":"selected-author-figure-and-final-abstract-check","checkedAt":"2026-10-19","evidenceUrl":"https://arxiv.org/pdf/2505.00623v1","note":"Author v1, 1 May 2025: selected methods and results, pages 1–4, read; page 4 Figure 3 visually checked. Final publisher abstract and publication date, 23 April 2026, checked. Final full text requires access; the attempted PDF returned HTML. Complete version comparison and spectral-weight calibration remain open."}},{"id":"source-8339743a9f1c3239","doi":"10.1007/JHEP08(2016)106","title":"A bound on chaos","year":2016,"url":"https://doi.org/10.1007/JHEP08(2016)106","publicationStatus":"journal-article","verification":{"scope":"primary-full-text-scoped-check","checkedAt":"2026-10-18","evidenceUrl":"https://link.springer.com/content/pdf/10.1007/JHEP08(2016)106.pdf","note":"Published version: Eq. (2.5), sections 4.1-4.2 and 4.3.3, printed pp. 5, 7-11. Checked the conditional chaos bound and its failure cases; not a transport measurement or an independent verification of the entire proof."}},{"id":"source-374c8bc13ced83e8","doi":"10.1038/s41586-021-03697-8","title":"Linear-in temperature resistivity from an isotropic Planckian scattering rate","year":2021,"url":"https://doi.org/10.1038/s41586-021-03697-8","publicationStatus":"journal-article","verification":{"scope":"selected-final-methods-results-and-figure-check","checkedAt":"2026-10-19","evidenceUrl":"https://warwick.ac.uk/fac/sci/physics/research/condensedmatt/supermag/pubs2021/Grissonnanche_Nature.595.667.2021.pdf","note":"Final results and selected methods read; printed page 669, Figure 2 visually checked. Compared selected author v2 passages. Temperature stability, absolute error, angular superconducting regions and fitted bandwidth distinguished. Complete fitting and raw-data reproduction remain open."}}],"materialCases":[{"formula":"overdoped cuprates","sample":"normal-state transport comparison","recordType":"experiment","tcK":null,"temperatureNote":"normal-state scattering study; no Tc record","criterion":"transport-scattering-inference","pressureRegime":"unknown","pressureGPa":null,"equilibrium":"equilibrium","probe":"resistivity plus Fermi-surface/effective-mass inputs","id":"scwiki-h2-material-1","sourceId":"source-c1ae7869b672a8e8","reportedTemperatureK":null,"temperatureKind":"normal-state","aliases":["cuprate","cuprates"]},{"id":"scwiki-h2-material-2","formula":"La1.35Nd0.4Sr0.25CuO4","sample":"Grissonnanche Nd-LSCO, 45 T angular magnetoresistance at p=0.24","recordType":"experiment","reportedTemperatureK":6,"tcK":null,"temperatureKind":"measurement","temperatureNote":"6 K measurement; superconducting angular sectors excluded. Absolute temperature uncertainty about ±1 K, distinct from ±1 mK stability.","criterion":"ADMR-measurement","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Angle-dependent c-axis magnetoresistance","sourceId":"source-374c8bc13ced83e8","aliases":["Nd-LSCO"]},{"id":"scwiki-h2-material-3","formula":"FeTe0.55Se0.45","sample":"Romero author v1, 100 nm film, selenium fraction x=0.45","recordType":"experiment","reportedTemperatureK":20,"tcK":null,"temperatureKind":"measurement","temperatureNote":"20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition.","criterion":"optical-linewidth-fit","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Terahertz conductivity, narrow Drude plus broad background","sourceId":"source-05b2d5ff6757b5eb","aliases":["FeTeSe","iron chalcogenide"]},{"id":"scwiki-h2-material-4","formula":"FeTe0.65Se0.35","sample":"Romero author v1, 100 nm film, selenium fraction x=0.35","recordType":"experiment","reportedTemperatureK":20,"tcK":null,"temperatureKind":"measurement","temperatureNote":"20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition.","criterion":"optical-linewidth-fit","pressureRegime":"ambient","pressureGPa":null,"equilibrium":"unknown","probe":"Terahertz conductivity, narrow Drude plus broad background","sourceId":"source-05b2d5ff6757b5eb","aliases":["FeTeSe","iron chalcogenide"]}],"claims":[{"id":"scwiki-h2-claim-scope-1","sectionId":"scope","statement":"A Planckian-scale claim compares a defined relaxation rate with $k_BT/\\hbar$. It must identify the observable, residual subtraction and uncertainty. Charge transport, optical response, single-particle decay and quantum scrambling need not share one lifetime. An approximate coefficient near unity is an empirical observation within a model, not a universal theorem obtained from a straight resistivity curve.","evidenceType":"theory","sourceIds":["source-67da95cac5481029"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-scope-2","sectionId":"scope","statement":"The evidence has several levels: measured conductivity, an extracted rate, a cross-material scaling relation, and a proposed bound. Moving between them adds assumptions. Bruin's transport comparison, Legros's cuprate analysis, angular magnetoresistance and frequency-resolved film measurements test different parts of this chain. A useful comparison retains each experiment's conditions instead of pooling every quoted coefficient.","evidenceType":"theory","sourceIds":["source-e6d342432f3409ae","source-c1ae7869b672a8e8","source-05b2d5ff6757b5eb","source-374c8bc13ced83e8"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-mathematical-assumptions-1","sectionId":"mathematical-assumptions","statement":"Write $\\gamma_{\\mathrm{tr}}=\\gamma_0+\\alpha_{\\mathrm{inel}}k_BT/\\hbar$. Then $\\alpha_{\\mathrm{tot}}=\\hbar\\gamma_{\\mathrm{tr}}/(k_BT)=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)$. A constant residual rate makes the total ratio temperature dependent even when the inelastic slope is fixed. Twenty-seven independent synthetic parameter checks verify this algebra; they do not justify additive scattering in a material.","evidenceType":"theory","sourceIds":["source-67da95cac5481029"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-mathematical-assumptions-2","sectionId":"mathematical-assumptions","statement":"With temperature-independent density and mass in a single-band Drude model, $\\rho=m^\\ast\\gamma_{\\mathrm{tr}}/(ne^2)$ gives $\\alpha_{\\mathrm{inel}}=(\\hbar ne^2/k_Bm^\\ast)d\\rho/dT$. A two-dimensional, spin-degenerate parabolic band instead uses sheet slope $A_1^\\square$, areal density $n_{2D}$ and $T_F=\\pi\\hbar^2n_{2D}/(m^\\ast k_B)$, yielding $A_1^\\square T_F=\\alpha_{\\mathrm{inel}}h/(2e^2)$. The geometric conversion and mass estimate are essential inputs, not outputs of a resistivity slope. Noncircular or multiple Fermi surfaces require additional analysis.","evidenceType":"theory","sourceIds":["source-c1ae7869b672a8e8"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-mathematical-assumptions-3","sectionId":"mathematical-assumptions","statement":"An independent angular-scattering illustration makes the lifetime distinction explicit. On a circular Fermi line, define an elastic event kernel $W(\\theta)=\\gamma[1+a\\cos\\theta]/(2\\pi)$ with $|a|\\leq1$. The event rate is $\\int_0^{2\\pi}W\\,d\\theta=\\gamma$, whereas current relaxation weights changes of direction: $\\int_0^{2\\pi}W(1-\\cos\\theta)\\,d\\theta=\\gamma(1-a/2)$. Fifteen numerical quadratures verify both integrals. Forward-weighted events therefore relax current less efficiently in this specified model. The event rate is explicitly defined; it is not silently identified with a spectral half-width. This elastic Boltzmann example proves neither a quantum bound nor a superconducting mechanism.","evidenceType":"theory","sourceIds":["source-67da95cac5481029"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-mathematical-assumptions-4","sectionId":"mathematical-assumptions","statement":"For a fitted Drude denominator $\\Gamma-i\\nu$, both variables use cycles per second. The corresponding decay rate is $\\gamma=2\\pi\\Gamma$, so $\\Gamma=\\alpha k_BT/h$ and $\\gamma=\\alpha k_BT/\\hbar$ have the same dimensionless coefficient after conversion. Mixing the conventions without converting the fitted width changes the apparent coefficient by $2\\pi$. Parallel channels add conductivities, further limiting inference from total resistance.","evidenceType":"theory","sourceIds":["source-05b2d5ff6757b5eb"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-experimental-criteria-1","sectionId":"experimental-criteria","statement":"Bruin and colleagues report linear resistivity in Sr3Ru2O7 at 7.9 T and use independently characterized Fermi-surface inputs to estimate scattering. The retrieved opening page describes a 1.5–400 K transport study and a field-induced nematic region below 1.2 K near that field. Those boundaries matter: the available page does not justify extending the measured law through the intervening phase or verify every cross-material fit. The remaining article pages and supplementary tables are outside this check.","evidenceType":"experiment","sourceIds":["source-e6d342432f3409ae"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-experimental-criteria-2","sectionId":"experimental-criteria","statement":"Legros's author manuscript compares sheet-resistance slopes with Fermi-temperature estimates. Its electron-doped comparison gives $\\alpha=1.0\\pm0.3$; the hole-doped estimates require more approximate geometry and specific-heat masses, with temperature-dependent mass an explicit complication in Nd-LSCO. The displayed $\\alpha=1$ prediction is a tested assumption, not an independent lifetime measurement. This article uses selected author-version passages; a complete comparison with the final publication remains open.","evidenceType":"experiment","sourceIds":["source-c1ae7869b672a8e8"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-experimental-criteria-3","sectionId":"experimental-criteria","statement":"Grissonnanche's final Nd-LSCO analysis separates an isotropic temperature-dependent component from anisotropic elastic scattering and reports $\\alpha=1.2\\pm0.4$. The band-energy scale is constrained by specific heat, and the quoted uncertainty includes fitting and sample-geometry contributions. Measurements at 45 T include superconducting angular sectors at the lower temperatures; those sectors are excluded. Neither a large applied field nor the isotropic inelastic term makes every datum normal-state or the total scattering isotropic.","evidenceType":"experiment","sourceIds":["source-374c8bc13ced83e8"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-experimental-criteria-4","sectionId":"experimental-criteria","statement":"Romero's author manuscript fits two FeTe1−xSex films over 20–40 K using a narrow Drude contribution plus a broad background. It reports cycle-frequency coefficients 3.02 for $x=0.45$ and 2.42 for $x=0.35$, with widths below 0.2 THz unresolved in its spectral window. These are author-version fit values, not newly reproduced final-paper estimates. The published abstract confirms a parallel-channel interpretation; complete version comparison and fitting covariance remain open. A linear narrow-channel width can coexist with nonlinear total resistivity.","evidenceType":"experiment","sourceIds":["source-05b2d5ff6757b5eb"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-limits-and-disputes-1","sectionId":"limits-and-disputes","statement":"The conditional chaos result $\\lambda_L\\leq2\\pi k_BT/\\hbar$ bounds exponential growth of a suitable regularized out-of-time-order correlator. Its argument requires thermal-strip analyticity and boundedness, controlled factorization errors and separated dissipation and scrambling scales. This is not a measured charge-transport rate; identifying the exponent with one requires another, model-specific argument. The theorem alone neither fixes a transport coefficient to one nor verifies a material's inferred mass.","evidenceType":"theory","sourceIds":["source-8339743a9f1c3239","source-67da95cac5481029"],"conditions":"Thermal quantum systems with a suitable regularized correlator, thermal-strip analyticity and boundedness, controlled factorization error and separated dissipation/scrambling scales. Exponential growth must exceed the error; no transport-time identification is assumed.","verificationScope":"Selected published MSS Eq. (2.5), sections 4.1–4.2 and 4.3.3, printed pp.5,7–11, inherited from the earlier H2 audit; Hartnoll-Mackenzie author v3 Section5. No independent verification of the complete proof."},{"id":"scwiki-h2-claim-limits-and-disputes-2","sectionId":"limits-and-disputes","statement":"Complete scientific acceptance remains open. Selected primary passages, figures and independent model checks do not constitute raw-data reproduction. Distinguish published results from the author's interpretation of universality; preserve unresolved frequency coverage, final-version and calibration limits. Spectral weight entering a condensate also does not identify the pairing mediator.","evidenceType":"theory","sourceIds":["source-e6d342432f3409ae","source-c1ae7869b672a8e8","source-05b2d5ff6757b5eb"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."},{"id":"scwiki-h2-claim-discovery-implications-1","sectionId":"discovery-implications","statement":"Compare rates only after aligning channel definitions, sample conditions and frequency units. Test whether alternative band weights or a temperature-dependent mass can explain the same measured curve. Then seek independent optical or angle-dependent constraints. A connection between normal-state relaxation and superconductivity is a research hypothesis to test; faster scattering does not, by itself, predict a higher transition temperature.","evidenceType":"hypothesis","sourceIds":["source-c1ae7869b672a8e8","source-05b2d5ff6757b5eb","source-374c8bc13ced83e8"],"conditions":"Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.","verificationScope":"Selected source passages and independent specified-model checks; not complete final-version or raw-data verification."}],"body":"## Scope\n\nA Planckian-scale claim compares a defined relaxation rate with $k_BT/\\hbar$. It must identify the observable, residual subtraction and uncertainty. Charge transport, optical response, single-particle decay and quantum scrambling need not share one lifetime. An approximate coefficient near unity is an empirical observation within a model, not a universal theorem obtained from a straight resistivity curve. [R1](#ref-source-67da95cac5481029)\n\nThe evidence has several levels: measured conductivity, an extracted rate, a cross-material scaling relation, and a proposed bound. Moving between them adds assumptions. Bruin's transport comparison, Legros's cuprate analysis, angular magnetoresistance and frequency-resolved film measurements test different parts of this chain. A useful comparison retains each experiment's conditions instead of pooling every quoted coefficient. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)\n\n## Mathematical assumptions\n\nWrite $\\gamma_{\\mathrm{tr}}=\\gamma_0+\\alpha_{\\mathrm{inel}}k_BT/\\hbar$. Then $\\alpha_{\\mathrm{tot}}=\\hbar\\gamma_{\\mathrm{tr}}/(k_BT)=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)$. A constant residual rate makes the total ratio temperature dependent even when the inelastic slope is fixed. Twenty-seven independent synthetic parameter checks verify this algebra; they do not justify additive scattering in a material. [R1](#ref-source-67da95cac5481029)\n\nWith temperature-independent density and mass in a single-band Drude model, $\\rho=m^\\ast\\gamma_{\\mathrm{tr}}/(ne^2)$ gives $\\alpha_{\\mathrm{inel}}=(\\hbar ne^2/k_Bm^\\ast)d\\rho/dT$. A two-dimensional, spin-degenerate parabolic band instead uses sheet slope $A_1^\\square$, areal density $n_{2D}$ and $T_F=\\pi\\hbar^2n_{2D}/(m^\\ast k_B)$, yielding $A_1^\\square T_F=\\alpha_{\\mathrm{inel}}h/(2e^2)$. The geometric conversion and mass estimate are essential inputs, not outputs of a resistivity slope. Noncircular or multiple Fermi surfaces require additional analysis. [R3](#ref-source-c1ae7869b672a8e8)\n\nAn independent angular-scattering illustration makes the lifetime distinction explicit. On a circular Fermi line, define an elastic event kernel $W(\\theta)=\\gamma[1+a\\cos\\theta]/(2\\pi)$ with $|a|\\leq1$. The event rate is $\\int_0^{2\\pi}W\\,d\\theta=\\gamma$, whereas current relaxation weights changes of direction: $\\int_0^{2\\pi}W(1-\\cos\\theta)\\,d\\theta=\\gamma(1-a/2)$. Fifteen numerical quadratures verify both integrals. Forward-weighted events therefore relax current less efficiently in this specified model. The event rate is explicitly defined; it is not silently identified with a spectral half-width. This elastic Boltzmann example proves neither a quantum bound nor a superconducting mechanism. [R1](#ref-source-67da95cac5481029)\n\nFor a fitted Drude denominator $\\Gamma-i\\nu$, both variables use cycles per second. The corresponding decay rate is $\\gamma=2\\pi\\Gamma$, so $\\Gamma=\\alpha k_BT/h$ and $\\gamma=\\alpha k_BT/\\hbar$ have the same dimensionless coefficient after conversion. Mixing the conventions without converting the fitted width changes the apparent coefficient by $2\\pi$. Parallel channels add conductivities, further limiting inference from total resistance. [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Experimental criteria\n\nBruin and colleagues report linear resistivity in Sr3Ru2O7 at 7.9 T and use independently characterized Fermi-surface inputs to estimate scattering. The retrieved opening page describes a 1.5–400 K transport study and a field-induced nematic region below 1.2 K near that field. Those boundaries matter: the available page does not justify extending the measured law through the intervening phase or verify every cross-material fit. The remaining article pages and supplementary tables are outside this check. [R2](#ref-source-e6d342432f3409ae)\n\nLegros's author manuscript compares sheet-resistance slopes with Fermi-temperature estimates. Its electron-doped comparison gives $\\alpha=1.0\\pm0.3$; the hole-doped estimates require more approximate geometry and specific-heat masses, with temperature-dependent mass an explicit complication in Nd-LSCO. The displayed $\\alpha=1$ prediction is a tested assumption, not an independent lifetime measurement. This article uses selected author-version passages; a complete comparison with the final publication remains open. [R3](#ref-source-c1ae7869b672a8e8)\n\nGrissonnanche's final Nd-LSCO analysis separates an isotropic temperature-dependent component from anisotropic elastic scattering and reports $\\alpha=1.2\\pm0.4$. The band-energy scale is constrained by specific heat, and the quoted uncertainty includes fitting and sample-geometry contributions. Measurements at 45 T include superconducting angular sectors at the lower temperatures; those sectors are excluded. Neither a large applied field nor the isotropic inelastic term makes every datum normal-state or the total scattering isotropic. [R6](#ref-source-374c8bc13ced83e8)\n\nRomero's author manuscript fits two FeTe1−xSex films over 20–40 K using a narrow Drude contribution plus a broad background. It reports cycle-frequency coefficients 3.02 for $x=0.45$ and 2.42 for $x=0.35$, with widths below 0.2 THz unresolved in its spectral window. These are author-version fit values, not newly reproduced final-paper estimates. The published abstract confirms a parallel-channel interpretation; complete version comparison and fitting covariance remain open. A linear narrow-channel width can coexist with nonlinear total resistivity. [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Limits and disputes\n\nThe conditional chaos result $\\lambda_L\\leq2\\pi k_BT/\\hbar$ bounds exponential growth of a suitable regularized out-of-time-order correlator. Its argument requires thermal-strip analyticity and boundedness, controlled factorization errors and separated dissipation and scrambling scales. This is not a measured charge-transport rate; identifying the exponent with one requires another, model-specific argument. The theorem alone neither fixes a transport coefficient to one nor verifies a material's inferred mass. [R5](#ref-source-8339743a9f1c3239) [R1](#ref-source-67da95cac5481029)\n\nComplete scientific acceptance remains open. Selected primary passages, figures and independent model checks do not constitute raw-data reproduction. Distinguish published results from the author's interpretation of universality; preserve unresolved frequency coverage, final-version and calibration limits. Spectral weight entering a condensate also does not identify the pairing mediator. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Discovery implications\n\nCompare rates only after aligning channel definitions, sample conditions and frequency units. Test whether alternative band weights or a temperature-dependent mass can explain the same measured curve. Then seek independent optical or angle-dependent constraints. A connection between normal-state relaxation and superconductivity is a research hypothesis to test; faster scattering does not, by itself, predict a higher transition temperature. [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)\n\n## Related topics\n\n[Strange metals](/scwiki/strange-metals), [Linear-T resistivity](/scwiki/linear-t-resistivity), and [Iron-based superconductors](/scwiki/iron-based-superconductors).","revision":"21e0ed3d03f7b5092d59","sections":[{"id":"scope","title":"Scope","markdown":"## Scope\n\nA Planckian-scale claim compares a defined relaxation rate with $k_BT/\\hbar$. It must identify the observable, residual subtraction and uncertainty. Charge transport, optical response, single-particle decay and quantum scrambling need not share one lifetime. An approximate coefficient near unity is an empirical observation within a model, not a universal theorem obtained from a straight resistivity curve. [R1](#ref-source-67da95cac5481029)\n\nThe evidence has several levels: measured conductivity, an extracted rate, a cross-material scaling relation, and a proposed bound. Moving between them adds assumptions. Bruin's transport comparison, Legros's cuprate analysis, angular magnetoresistance and frequency-resolved film measurements test different parts of this chain. A useful comparison retains each experiment's conditions instead of pooling every quoted coefficient. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)"},{"id":"mathematical-assumptions","title":"Mathematical assumptions","markdown":"## Mathematical assumptions\n\nWrite $\\gamma_{\\mathrm{tr}}=\\gamma_0+\\alpha_{\\mathrm{inel}}k_BT/\\hbar$. Then $\\alpha_{\\mathrm{tot}}=\\hbar\\gamma_{\\mathrm{tr}}/(k_BT)=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)$. A constant residual rate makes the total ratio temperature dependent even when the inelastic slope is fixed. Twenty-seven independent synthetic parameter checks verify this algebra; they do not justify additive scattering in a material. [R1](#ref-source-67da95cac5481029)\n\nWith temperature-independent density and mass in a single-band Drude model, $\\rho=m^\\ast\\gamma_{\\mathrm{tr}}/(ne^2)$ gives $\\alpha_{\\mathrm{inel}}=(\\hbar ne^2/k_Bm^\\ast)d\\rho/dT$. A two-dimensional, spin-degenerate parabolic band instead uses sheet slope $A_1^\\square$, areal density $n_{2D}$ and $T_F=\\pi\\hbar^2n_{2D}/(m^\\ast k_B)$, yielding $A_1^\\square T_F=\\alpha_{\\mathrm{inel}}h/(2e^2)$. The geometric conversion and mass estimate are essential inputs, not outputs of a resistivity slope. Noncircular or multiple Fermi surfaces require additional analysis. [R3](#ref-source-c1ae7869b672a8e8)\n\nAn independent angular-scattering illustration makes the lifetime distinction explicit. On a circular Fermi line, define an elastic event kernel $W(\\theta)=\\gamma[1+a\\cos\\theta]/(2\\pi)$ with $|a|\\leq1$. The event rate is $\\int_0^{2\\pi}W\\,d\\theta=\\gamma$, whereas current relaxation weights changes of direction: $\\int_0^{2\\pi}W(1-\\cos\\theta)\\,d\\theta=\\gamma(1-a/2)$. Fifteen numerical quadratures verify both integrals. Forward-weighted events therefore relax current less efficiently in this specified model. The event rate is explicitly defined; it is not silently identified with a spectral half-width. This elastic Boltzmann example proves neither a quantum bound nor a superconducting mechanism. [R1](#ref-source-67da95cac5481029)\n\nFor a fitted Drude denominator $\\Gamma-i\\nu$, both variables use cycles per second. The corresponding decay rate is $\\gamma=2\\pi\\Gamma$, so $\\Gamma=\\alpha k_BT/h$ and $\\gamma=\\alpha k_BT/\\hbar$ have the same dimensionless coefficient after conversion. Mixing the conventions without converting the fitted width changes the apparent coefficient by $2\\pi$. Parallel channels add conductivities, further limiting inference from total resistance. [R4](#ref-source-05b2d5ff6757b5eb)"},{"id":"experimental-criteria","title":"Experimental criteria","markdown":"## Experimental criteria\n\nBruin and colleagues report linear resistivity in Sr3Ru2O7 at 7.9 T and use independently characterized Fermi-surface inputs to estimate scattering. The retrieved opening page describes a 1.5–400 K transport study and a field-induced nematic region below 1.2 K near that field. Those boundaries matter: the available page does not justify extending the measured law through the intervening phase or verify every cross-material fit. The remaining article pages and supplementary tables are outside this check. [R2](#ref-source-e6d342432f3409ae)\n\nLegros's author manuscript compares sheet-resistance slopes with Fermi-temperature estimates. Its electron-doped comparison gives $\\alpha=1.0\\pm0.3$; the hole-doped estimates require more approximate geometry and specific-heat masses, with temperature-dependent mass an explicit complication in Nd-LSCO. The displayed $\\alpha=1$ prediction is a tested assumption, not an independent lifetime measurement. This article uses selected author-version passages; a complete comparison with the final publication remains open. [R3](#ref-source-c1ae7869b672a8e8)\n\nGrissonnanche's final Nd-LSCO analysis separates an isotropic temperature-dependent component from anisotropic elastic scattering and reports $\\alpha=1.2\\pm0.4$. The band-energy scale is constrained by specific heat, and the quoted uncertainty includes fitting and sample-geometry contributions. Measurements at 45 T include superconducting angular sectors at the lower temperatures; those sectors are excluded. Neither a large applied field nor the isotropic inelastic term makes every datum normal-state or the total scattering isotropic. [R6](#ref-source-374c8bc13ced83e8)\n\nRomero's author manuscript fits two FeTe1−xSex films over 20–40 K using a narrow Drude contribution plus a broad background. It reports cycle-frequency coefficients 3.02 for $x=0.45$ and 2.42 for $x=0.35$, with widths below 0.2 THz unresolved in its spectral window. These are author-version fit values, not newly reproduced final-paper estimates. The published abstract confirms a parallel-channel interpretation; complete version comparison and fitting covariance remain open. A linear narrow-channel width can coexist with nonlinear total resistivity. [R4](#ref-source-05b2d5ff6757b5eb)"},{"id":"limits-and-disputes","title":"Limits and disputes","markdown":"## Limits and disputes\n\nThe conditional chaos result $\\lambda_L\\leq2\\pi k_BT/\\hbar$ bounds exponential growth of a suitable regularized out-of-time-order correlator. Its argument requires thermal-strip analyticity and boundedness, controlled factorization errors and separated dissipation and scrambling scales. This is not a measured charge-transport rate; identifying the exponent with one requires another, model-specific argument. The theorem alone neither fixes a transport coefficient to one nor verifies a material's inferred mass. [R5](#ref-source-8339743a9f1c3239) [R1](#ref-source-67da95cac5481029)\n\nComplete scientific acceptance remains open. Selected primary passages, figures and independent model checks do not constitute raw-data reproduction. Distinguish published results from the author's interpretation of universality; preserve unresolved frequency coverage, final-version and calibration limits. Spectral weight entering a condensate also does not identify the pairing mediator. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb)"},{"id":"discovery-implications","title":"Discovery implications","markdown":"## Discovery implications\n\nCompare rates only after aligning channel definitions, sample conditions and frequency units. Test whether alternative band weights or a temperature-dependent mass can explain the same measured curve. Then seek independent optical or angle-dependent constraints. A connection between normal-state relaxation and superconductivity is a research hypothesis to test; faster scattering does not, by itself, predict a higher transition temperature. [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)"},{"id":"related-topics","title":"Related topics","markdown":"## Related topics\n\n[Strange metals](/scwiki/strange-metals), [Linear-T resistivity](/scwiki/linear-t-resistivity), and [Iron-based superconductors](/scwiki/iron-based-superconductors)."},{"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| overdoped cuprates (aliases: cuprate, cuprates); normal-state transport comparison | normal-state scattering study; no Tc record | normal-state; transport-scattering-inference | resistivity plus Fermi-surface/effective-mass inputs | unknown; unknown GPa | equilibrium | experiment; [source](#ref-source-c1ae7869b672a8e8) |\n| La1.35Nd0.4Sr0.25CuO4 (aliases: Nd-LSCO); Grissonnanche Nd-LSCO, 45 T angular magnetoresistance at p=0.24 | 6 K; 6 K measurement; superconducting angular sectors excluded. Absolute temperature uncertainty about ±1 K, distinct from ±1 mK stability. | measurement; ADMR-measurement | Angle-dependent c-axis magnetoresistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-374c8bc13ced83e8) |\n| FeTe0.55Se0.45 (aliases: FeTeSe, iron chalcogenide); Romero author v1, 100 nm film, selenium fraction x=0.45 | 20 K; 20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition. | measurement; optical-linewidth-fit | Terahertz conductivity, narrow Drude plus broad background | ambient; unknown GPa | unknown | experiment; [source](#ref-source-05b2d5ff6757b5eb) |\n| FeTe0.65Se0.35 (aliases: FeTeSe, iron chalcogenide); Romero author v1, 100 nm film, selenium fraction x=0.35 | 20 K; 20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition. | measurement; optical-linewidth-fit | Terahertz conductivity, narrow Drude plus broad background | ambient; unknown GPa | unknown | experiment; [source](#ref-source-05b2d5ff6757b5eb) |"}],"markdown":"# Planckian dissipation: definitions and inference\n\nA linear resistivity does not by itself measure a Planckian lifetime. Specify the relaxation channel, residual rate, frequency convention and transport model.\n\n## Scope\n\nA Planckian-scale claim compares a defined relaxation rate with $k_BT/\\hbar$. It must identify the observable, residual subtraction and uncertainty. Charge transport, optical response, single-particle decay and quantum scrambling need not share one lifetime. An approximate coefficient near unity is an empirical observation within a model, not a universal theorem obtained from a straight resistivity curve. [R1](#ref-source-67da95cac5481029)\n\nThe evidence has several levels: measured conductivity, an extracted rate, a cross-material scaling relation, and a proposed bound. Moving between them adds assumptions. Bruin's transport comparison, Legros's cuprate analysis, angular magnetoresistance and frequency-resolved film measurements test different parts of this chain. A useful comparison retains each experiment's conditions instead of pooling every quoted coefficient. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)\n\n## Mathematical assumptions\n\nWrite $\\gamma_{\\mathrm{tr}}=\\gamma_0+\\alpha_{\\mathrm{inel}}k_BT/\\hbar$. Then $\\alpha_{\\mathrm{tot}}=\\hbar\\gamma_{\\mathrm{tr}}/(k_BT)=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)$. A constant residual rate makes the total ratio temperature dependent even when the inelastic slope is fixed. Twenty-seven independent synthetic parameter checks verify this algebra; they do not justify additive scattering in a material. [R1](#ref-source-67da95cac5481029)\n\nWith temperature-independent density and mass in a single-band Drude model, $\\rho=m^\\ast\\gamma_{\\mathrm{tr}}/(ne^2)$ gives $\\alpha_{\\mathrm{inel}}=(\\hbar ne^2/k_Bm^\\ast)d\\rho/dT$. A two-dimensional, spin-degenerate parabolic band instead uses sheet slope $A_1^\\square$, areal density $n_{2D}$ and $T_F=\\pi\\hbar^2n_{2D}/(m^\\ast k_B)$, yielding $A_1^\\square T_F=\\alpha_{\\mathrm{inel}}h/(2e^2)$. The geometric conversion and mass estimate are essential inputs, not outputs of a resistivity slope. Noncircular or multiple Fermi surfaces require additional analysis. [R3](#ref-source-c1ae7869b672a8e8)\n\nAn independent angular-scattering illustration makes the lifetime distinction explicit. On a circular Fermi line, define an elastic event kernel $W(\\theta)=\\gamma[1+a\\cos\\theta]/(2\\pi)$ with $|a|\\leq1$. The event rate is $\\int_0^{2\\pi}W\\,d\\theta=\\gamma$, whereas current relaxation weights changes of direction: $\\int_0^{2\\pi}W(1-\\cos\\theta)\\,d\\theta=\\gamma(1-a/2)$. Fifteen numerical quadratures verify both integrals. Forward-weighted events therefore relax current less efficiently in this specified model. The event rate is explicitly defined; it is not silently identified with a spectral half-width. This elastic Boltzmann example proves neither a quantum bound nor a superconducting mechanism. [R1](#ref-source-67da95cac5481029)\n\nFor a fitted Drude denominator $\\Gamma-i\\nu$, both variables use cycles per second. The corresponding decay rate is $\\gamma=2\\pi\\Gamma$, so $\\Gamma=\\alpha k_BT/h$ and $\\gamma=\\alpha k_BT/\\hbar$ have the same dimensionless coefficient after conversion. Mixing the conventions without converting the fitted width changes the apparent coefficient by $2\\pi$. Parallel channels add conductivities, further limiting inference from total resistance. [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Experimental criteria\n\nBruin and colleagues report linear resistivity in Sr3Ru2O7 at 7.9 T and use independently characterized Fermi-surface inputs to estimate scattering. The retrieved opening page describes a 1.5–400 K transport study and a field-induced nematic region below 1.2 K near that field. Those boundaries matter: the available page does not justify extending the measured law through the intervening phase or verify every cross-material fit. The remaining article pages and supplementary tables are outside this check. [R2](#ref-source-e6d342432f3409ae)\n\nLegros's author manuscript compares sheet-resistance slopes with Fermi-temperature estimates. Its electron-doped comparison gives $\\alpha=1.0\\pm0.3$; the hole-doped estimates require more approximate geometry and specific-heat masses, with temperature-dependent mass an explicit complication in Nd-LSCO. The displayed $\\alpha=1$ prediction is a tested assumption, not an independent lifetime measurement. This article uses selected author-version passages; a complete comparison with the final publication remains open. [R3](#ref-source-c1ae7869b672a8e8)\n\nGrissonnanche's final Nd-LSCO analysis separates an isotropic temperature-dependent component from anisotropic elastic scattering and reports $\\alpha=1.2\\pm0.4$. The band-energy scale is constrained by specific heat, and the quoted uncertainty includes fitting and sample-geometry contributions. Measurements at 45 T include superconducting angular sectors at the lower temperatures; those sectors are excluded. Neither a large applied field nor the isotropic inelastic term makes every datum normal-state or the total scattering isotropic. [R6](#ref-source-374c8bc13ced83e8)\n\nRomero's author manuscript fits two FeTe1−xSex films over 20–40 K using a narrow Drude contribution plus a broad background. It reports cycle-frequency coefficients 3.02 for $x=0.45$ and 2.42 for $x=0.35$, with widths below 0.2 THz unresolved in its spectral window. These are author-version fit values, not newly reproduced final-paper estimates. The published abstract confirms a parallel-channel interpretation; complete version comparison and fitting covariance remain open. A linear narrow-channel width can coexist with nonlinear total resistivity. [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Limits and disputes\n\nThe conditional chaos result $\\lambda_L\\leq2\\pi k_BT/\\hbar$ bounds exponential growth of a suitable regularized out-of-time-order correlator. Its argument requires thermal-strip analyticity and boundedness, controlled factorization errors and separated dissipation and scrambling scales. This is not a measured charge-transport rate; identifying the exponent with one requires another, model-specific argument. The theorem alone neither fixes a transport coefficient to one nor verifies a material's inferred mass. [R5](#ref-source-8339743a9f1c3239) [R1](#ref-source-67da95cac5481029)\n\nComplete scientific acceptance remains open. Selected primary passages, figures and independent model checks do not constitute raw-data reproduction. Distinguish published results from the author's interpretation of universality; preserve unresolved frequency coverage, final-version and calibration limits. Spectral weight entering a condensate also does not identify the pairing mediator. [R2](#ref-source-e6d342432f3409ae) [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb)\n\n## Discovery implications\n\nCompare rates only after aligning channel definitions, sample conditions and frequency units. Test whether alternative band weights or a temperature-dependent mass can explain the same measured curve. Then seek independent optical or angle-dependent constraints. A connection between normal-state relaxation and superconductivity is a research hypothesis to test; faster scattering does not, by itself, predict a higher transition temperature. [R3](#ref-source-c1ae7869b672a8e8) [R4](#ref-source-05b2d5ff6757b5eb) [R6](#ref-source-374c8bc13ced83e8)\n\n## Related topics\n\n[Strange metals](/scwiki/strange-metals), [Linear-T resistivity](/scwiki/linear-t-resistivity), and [Iron-based superconductors](/scwiki/iron-based-superconductors).\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| overdoped cuprates (aliases: cuprate, cuprates); normal-state transport comparison | normal-state scattering study; no Tc record | normal-state; transport-scattering-inference | resistivity plus Fermi-surface/effective-mass inputs | unknown; unknown GPa | equilibrium | experiment; [source](#ref-source-c1ae7869b672a8e8) |\n| La1.35Nd0.4Sr0.25CuO4 (aliases: Nd-LSCO); Grissonnanche Nd-LSCO, 45 T angular magnetoresistance at p=0.24 | 6 K; 6 K measurement; superconducting angular sectors excluded. Absolute temperature uncertainty about ±1 K, distinct from ±1 mK stability. | measurement; ADMR-measurement | Angle-dependent c-axis magnetoresistance | ambient; unknown GPa | unknown | experiment; [source](#ref-source-374c8bc13ced83e8) |\n| FeTe0.55Se0.45 (aliases: FeTeSe, iron chalcogenide); Romero author v1, 100 nm film, selenium fraction x=0.45 | 20 K; 20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition. | measurement; optical-linewidth-fit | Terahertz conductivity, narrow Drude plus broad background | ambient; unknown GPa | unknown | experiment; [source](#ref-source-05b2d5ff6757b5eb) |\n| FeTe0.65Se0.35 (aliases: FeTeSe, iron chalcogenide); Romero author v1, 100 nm film, selenium fraction x=0.35 | 20 K; 20 K is the lower edge of the 20–40 K linewidth-fitting interval; not a superconducting transition. | measurement; optical-linewidth-fit | Terahertz conductivity, narrow Drude plus broad background | ambient; unknown GPa | unknown | experiment; [source](#ref-source-05b2d5ff6757b5eb) |\n\n## Sources\n\n### Ref source-67da95cac5481029\n\n[R1] Colloquium: Planckian dissipation in metals (2022). [DOI 10.1103/RevModPhys.94.041002](https://doi.org/10.1103/RevModPhys.94.041002). Publication: journal-article. Check: review-full-text-scoped-check. Checked: 2026-10-18. Author manuscript v3 (18 June 2022), sections 1.4, 4, 4.1 and 5, Eqs. (28)-(32): residual subtraction, distinct lifetimes, effective-mass/vertex caveats, and chaos versus transport. This review-level check does not verify the underlying experiments or every statement in H2.\n### Ref source-e6d342432f3409ae\n\n[R2] Similarity of Scattering Rates in Metals Showing T-Linear Resistivity (2013). [DOI 10.1126/science.1227612](https://doi.org/10.1126/science.1227612). Publication: journal-article. Check: selected-final-opening-page-check. Checked: 2026-10-19. Printed page 804 (PDF page 5) read and visually checked: abstract and opening discussion. This download mostly contains an adjacent article and does not include pages 805–807. Figure fits and supplementary parameter tables remain unaudited. Author institutional record confirms 15 February 2013.\n### Ref source-c1ae7869b672a8e8\n\n[R3] Universal T-linear resistivity and Planckian dissipation in overdoped cuprates (2019). [DOI 10.1038/s41567-018-0334-2](https://doi.org/10.1038/s41567-018-0334-2). Publication: journal-article. Check: earlier-author-manuscript-scoped-check. Checked: 2026-10-18. Selected v1 pp. 4, 7–8 and Figs. 1–2 captions: Drude assumptions, film method and magnetoresistance correction. Published volume year 2019; final-version comparison and complete data fitting remain open. H2 additionally checked v1 pp.4–5, Eq.(1), mass estimates and uncertainty discussion. Final PDF attempts were unavailable; no final full-text comparison is claimed.\n### Ref source-05b2d5ff6757b5eb\n\n[R4] Planckian scattering and parallel conduction channels in an iron chalcogenide superconductor (2026). [DOI 10.1038/s41567-026-03266-8](https://doi.org/10.1038/s41567-026-03266-8). Publication: journal-article. Check: selected-author-figure-and-final-abstract-check. Checked: 2026-10-19. Author v1, 1 May 2025: selected methods and results, pages 1–4, read; page 4 Figure 3 visually checked. Final publisher abstract and publication date, 23 April 2026, checked. Final full text requires access; the attempted PDF returned HTML. Complete version comparison and spectral-weight calibration remain open.\n### Ref source-8339743a9f1c3239\n\n[R5] A bound on chaos (2016). [DOI 10.1007/JHEP08(2016)106](https://doi.org/10.1007/JHEP08(2016)106). Publication: journal-article. Check: primary-full-text-scoped-check. Checked: 2026-10-18. Published version: Eq. (2.5), sections 4.1-4.2 and 4.3.3, printed pp. 5, 7-11. Checked the conditional chaos bound and its failure cases; not a transport measurement or an independent verification of the entire proof.\n### Ref source-374c8bc13ced83e8\n\n[R6] Linear-in temperature resistivity from an isotropic Planckian scattering rate (2021). [DOI 10.1038/s41586-021-03697-8](https://doi.org/10.1038/s41586-021-03697-8). Publication: journal-article. Check: selected-final-methods-results-and-figure-check. Checked: 2026-10-19. Final results and selected methods read; printed page 669, Figure 2 visually checked. Compared selected author v2 passages. Temperature stability, absolute error, angular superconducting regions and fitted bandwidth distinguished. Complete fitting and raw-data reproduction remain open.\n\n## Claim evidence and conditions\n\n### scwiki-h2-claim-scope-1\n\nA Planckian-scale claim compares a defined relaxation rate with $k_BT/\\hbar$. It must identify the observable, residual subtraction and uncertainty. Charge transport, optical response, single-particle decay and quantum scrambling need not share one lifetime. An approximate coefficient near unity is an empirical observation within a model, not a universal theorem obtained from a straight resistivity curve.\n\nEvidence: theory. Sources: source-67da95cac5481029.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-scope-2\n\nThe evidence has several levels: measured conductivity, an extracted rate, a cross-material scaling relation, and a proposed bound. Moving between them adds assumptions. Bruin's transport comparison, Legros's cuprate analysis, angular magnetoresistance and frequency-resolved film measurements test different parts of this chain. A useful comparison retains each experiment's conditions instead of pooling every quoted coefficient.\n\nEvidence: theory. Sources: source-e6d342432f3409ae, source-c1ae7869b672a8e8, source-05b2d5ff6757b5eb, source-374c8bc13ced83e8.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-mathematical-assumptions-1\n\nWrite $\\gamma_{\\mathrm{tr}}=\\gamma_0+\\alpha_{\\mathrm{inel}}k_BT/\\hbar$. Then $\\alpha_{\\mathrm{tot}}=\\hbar\\gamma_{\\mathrm{tr}}/(k_BT)=\\alpha_{\\mathrm{inel}}+\\hbar\\gamma_0/(k_BT)$. A constant residual rate makes the total ratio temperature dependent even when the inelastic slope is fixed. Twenty-seven independent synthetic parameter checks verify this algebra; they do not justify additive scattering in a material.\n\nEvidence: theory. Sources: source-67da95cac5481029.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-mathematical-assumptions-2\n\nWith temperature-independent density and mass in a single-band Drude model, $\\rho=m^\\ast\\gamma_{\\mathrm{tr}}/(ne^2)$ gives $\\alpha_{\\mathrm{inel}}=(\\hbar ne^2/k_Bm^\\ast)d\\rho/dT$. A two-dimensional, spin-degenerate parabolic band instead uses sheet slope $A_1^\\square$, areal density $n_{2D}$ and $T_F=\\pi\\hbar^2n_{2D}/(m^\\ast k_B)$, yielding $A_1^\\square T_F=\\alpha_{\\mathrm{inel}}h/(2e^2)$. The geometric conversion and mass estimate are essential inputs, not outputs of a resistivity slope. Noncircular or multiple Fermi surfaces require additional analysis.\n\nEvidence: theory. Sources: source-c1ae7869b672a8e8.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-mathematical-assumptions-3\n\nAn independent angular-scattering illustration makes the lifetime distinction explicit. On a circular Fermi line, define an elastic event kernel $W(\\theta)=\\gamma[1+a\\cos\\theta]/(2\\pi)$ with $|a|\\leq1$. The event rate is $\\int_0^{2\\pi}W\\,d\\theta=\\gamma$, whereas current relaxation weights changes of direction: $\\int_0^{2\\pi}W(1-\\cos\\theta)\\,d\\theta=\\gamma(1-a/2)$. Fifteen numerical quadratures verify both integrals. Forward-weighted events therefore relax current less efficiently in this specified model. The event rate is explicitly defined; it is not silently identified with a spectral half-width. This elastic Boltzmann example proves neither a quantum bound nor a superconducting mechanism.\n\nEvidence: theory. Sources: source-67da95cac5481029.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-mathematical-assumptions-4\n\nFor a fitted Drude denominator $\\Gamma-i\\nu$, both variables use cycles per second. The corresponding decay rate is $\\gamma=2\\pi\\Gamma$, so $\\Gamma=\\alpha k_BT/h$ and $\\gamma=\\alpha k_BT/\\hbar$ have the same dimensionless coefficient after conversion. Mixing the conventions without converting the fitted width changes the apparent coefficient by $2\\pi$. Parallel channels add conductivities, further limiting inference from total resistance.\n\nEvidence: theory. Sources: source-05b2d5ff6757b5eb.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-experimental-criteria-1\n\nBruin and colleagues report linear resistivity in Sr3Ru2O7 at 7.9 T and use independently characterized Fermi-surface inputs to estimate scattering. The retrieved opening page describes a 1.5–400 K transport study and a field-induced nematic region below 1.2 K near that field. Those boundaries matter: the available page does not justify extending the measured law through the intervening phase or verify every cross-material fit. The remaining article pages and supplementary tables are outside this check.\n\nEvidence: experiment. Sources: source-e6d342432f3409ae.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-experimental-criteria-2\n\nLegros's author manuscript compares sheet-resistance slopes with Fermi-temperature estimates. Its electron-doped comparison gives $\\alpha=1.0\\pm0.3$; the hole-doped estimates require more approximate geometry and specific-heat masses, with temperature-dependent mass an explicit complication in Nd-LSCO. The displayed $\\alpha=1$ prediction is a tested assumption, not an independent lifetime measurement. This article uses selected author-version passages; a complete comparison with the final publication remains open.\n\nEvidence: experiment. Sources: source-c1ae7869b672a8e8.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-experimental-criteria-3\n\nGrissonnanche's final Nd-LSCO analysis separates an isotropic temperature-dependent component from anisotropic elastic scattering and reports $\\alpha=1.2\\pm0.4$. The band-energy scale is constrained by specific heat, and the quoted uncertainty includes fitting and sample-geometry contributions. Measurements at 45 T include superconducting angular sectors at the lower temperatures; those sectors are excluded. Neither a large applied field nor the isotropic inelastic term makes every datum normal-state or the total scattering isotropic.\n\nEvidence: experiment. Sources: source-374c8bc13ced83e8.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-experimental-criteria-4\n\nRomero's author manuscript fits two FeTe1−xSex films over 20–40 K using a narrow Drude contribution plus a broad background. It reports cycle-frequency coefficients 3.02 for $x=0.45$ and 2.42 for $x=0.35$, with widths below 0.2 THz unresolved in its spectral window. These are author-version fit values, not newly reproduced final-paper estimates. The published abstract confirms a parallel-channel interpretation; complete version comparison and fitting covariance remain open. A linear narrow-channel width can coexist with nonlinear total resistivity.\n\nEvidence: experiment. Sources: source-05b2d5ff6757b5eb.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-limits-and-disputes-1\n\nThe conditional chaos result $\\lambda_L\\leq2\\pi k_BT/\\hbar$ bounds exponential growth of a suitable regularized out-of-time-order correlator. Its argument requires thermal-strip analyticity and boundedness, controlled factorization errors and separated dissipation and scrambling scales. This is not a measured charge-transport rate; identifying the exponent with one requires another, model-specific argument. The theorem alone neither fixes a transport coefficient to one nor verifies a material's inferred mass.\n\nEvidence: theory. Sources: source-8339743a9f1c3239, source-67da95cac5481029.\n\nConditions: Thermal quantum systems with a suitable regularized correlator, thermal-strip analyticity and boundedness, controlled factorization error and separated dissipation/scrambling scales. Exponential growth must exceed the error; no transport-time identification is assumed.\n\nVerification scope: Selected published MSS Eq. (2.5), sections 4.1–4.2 and 4.3.3, printed pp.5,7–11, inherited from the earlier H2 audit; Hartnoll-Mackenzie author v3 Section5. No independent verification of the complete proof.\n\n### scwiki-h2-claim-limits-and-disputes-2\n\nComplete scientific acceptance remains open. Selected primary passages, figures and independent model checks do not constitute raw-data reproduction. Distinguish published results from the author's interpretation of universality; preserve unresolved frequency coverage, final-version and calibration limits. Spectral weight entering a condensate also does not identify the pairing mediator.\n\nEvidence: theory. Sources: source-e6d342432f3409ae, source-c1ae7869b672a8e8, source-05b2d5ff6757b5eb.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n### scwiki-h2-claim-discovery-implications-1\n\nCompare rates only after aligning channel definitions, sample conditions and frequency units. Test whether alternative band weights or a temperature-dependent mass can explain the same measured curve. Then seek independent optical or angle-dependent constraints. A connection between normal-state relaxation and superconductivity is a research hypothesis to test; faster scattering does not, by itself, predict a higher transition temperature.\n\nEvidence: hypothesis. Sources: source-c1ae7869b672a8e8, source-05b2d5ff6757b5eb, source-374c8bc13ced83e8.\n\nConditions: Defined transport/optical/event/chaos channel, residual subtraction, frequency units, fitting window and source version.\n\nVerification scope: Selected source passages and independent specified-model checks; not complete final-version or raw-data verification.\n\n## Revision and review\n\nArticle ID: scwiki-h2. Revision: 21e0ed3d03f7b5092d59. Updated: 2026-10-18T16:34:01.759993+00:00.\n\nReview scope: Selected Bruin opening page, Legros author scaling passages, inherited final Nd-LSCO and author FeTeSe figure checks, conditional chaos theorem passages and independent lifetime-model checks.\n\n- Complete scientific acceptance remains open.\n- Bruin pages805–807 and supplementary tables were not retrieved in the selected PDF.\n- Legros and Romero final-version comparison, fitting covariance and raw-data reproduction remain incomplete.\n- Elastic event-model and residual-rate checks do not establish universal transport or chaos bounds.\n\nSource: [H_anomalous_normal_state/H2_Planckian_limit.md](https://github.com/JackZH26/jzis-superconductivity/blob/0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf/H_anomalous_normal_state/H2_Planckian_limit.md), commit 0a7c9d6696804ec26aa12f8eed68b55c9b3c0fcf, SHA-256 25c50026c1a52dd82561048516dabc03c0ecee3dba8044d90552cea0fdb59f28.\n","wordCount":829}}