2025/03/19 by Dipanjan Chaudhuri, Chaudhuri, Dipanjan, David Barbalas +17 · 2 citations
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2503.15646
openalex publication_date 2025/03/19 · openalex created_date 2025/10/17 · openalex updated_date 2026/07/28
Understanding the T-linear normal-state resistivity of cuprates remains a central physics challenge. The associated momentum relaxation rate, ΓM, saturates near the conjectured ``Planckian" bound ΓM∼ kT/ℏ, but the mechanism underlying the anomalous scattering remains unresolved. Here we employ nonlinear terahertz spectroscopy to systematically study La2-xSrxCuO4 across a broad temperature and doping range. We measure the normal-state third-order susceptibility, |χ(3)|≈ 6×10-9 m2/V2, among the largest in the THz regime, enabling direct access to the rarely measured electronic energy relaxation rate, ΓE. Strikingly, ΓE is 10-40 times smaller than ΓM, revealing that the scatterings responsible for momentum loss and T-linear resistivity do not remove appreciable energy from the electrons. While ΓM (T) is consistent with quasi-elastic scattering from bosonic modes above their characteristic energy scale, this is incompatible with the increasing temperature dependence of ΓE(T). Our results exclude phonons as the source of T-linear resistivity and impose strong constraints on possible mechanisms.