We present a study of low-temperature electric and thermal transport in RuO2, a metallic oxide which has attracted much recent attention. Careful scrutiny of electric resistivity reveals a quadratic temperature dependence below ∼ 20 K undetected in previous studies of electronic transport in this material. The prefactor of this T2 resistivity, given the electronic specific heat, corresponds to what is expected by the Kadowaki-Woods scaling. The variation of its amplitude across 4 different samples is negligible despite an eightfold variation of residual resistivity. There is also a T5 resistivity due to scattering by phonons. By measuring thermal conductivity, κ, at zero field and at 12 T, we separated its electronic and the phononic components and found that the electronic component respects the Wiedemann-Franz law at zero temperature and deviates downward at finite temperature. The latter corresponds to a threefold discrepancy between the prefactors of the two (thermal and electric) T-square resistivities. Our results, establishing RuO2 as a weakly correlated Fermi liquid, provide new input for the ongoing theoretical attempt to give a quantitative account of electron-electron scattering in metallic oxides starting from first principles.
@article{arxiv.2511.04278,
title = {T-square electric resistivity and its thermal counterpart in RuO$_2$},
author = {Yu Ling and Florent Pawula and Ramzy Daou and Benoît Fauqué and Kamran Behnia},
journal= {arXiv preprint arXiv:2511.04278},
year = {2026}
}