2025/12/02 by Paul, Shubhankar, Ikeda, Atsutoshi, Matsuki, Hisakazu +5
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2512.03108
The magnetic nature of the altermagnet candidate RuO2 remains under debate. It has been recently shown from quantum oscillations and angle-resolved photoemission spectroscopy (ARPES) that the high-quality RuO2 bulk single crystal is a paramagnetic metal. However, the low-temperature specific heat exhibits a clear deviation from the conventional C(T)=γT + βT3 dependence; it is well described with nonanalytic Fermi-liquid correction for a clean paramagnetic metal: C(T) = γT + βT3 + δT3 \textrmln(T/T^*). Correspondingly, the magnetic susceptibility is well fitted with the inclusion of T2\textrmlnT term as well as H2lnH term. In contrast to the spin fluctuation mechanism applicable to some heavy-electron compounds with positive δ, RuO2 shows negative δ suggesting a different origin. The observation of such nonanalytic Fermi liquid corrections is attributable to the availability of an ultra-clean sample. The electronic specific heat, the magnetic susceptibility, and the T2 coefficient in resistivity point to a weakly-correlated 3D Fermi-liquid state with a modest electron correlation, as supported by the Wilson and Kadowaki-Woods ratios.