Non-Fermi liquid behavior and scaling of low frequency suppression in optical conductivity spectra of CaRuO$_3$

TL;DR

This study investigates the optical conductivity of CaRuO$_3$, revealing non-Fermi liquid behavior at low temperatures and a universal $\omega / T$ scaling of low-frequency suppression across various temperatures.

Contribution

It demonstrates the $\omega / T$ scaling in optical conductivity spectra of CaRuO$_3$, linking non-Fermi liquid behavior with temperature-dependent spectral suppression.

Findings

Non-Fermi liquid behavior with $\sigma_1(\omega)\sim 1/\omega^{1/2}$ at 10 K

Progressive suppression of $\sigma_1(\omega)$ with increasing temperature

Universal $\omega / T$ scaling of low-frequency spectra

Abstract

Optical conductivity spectra $\sigma_1(\omega)$ of paramagnetic CaRuO$_3$ are investigated at various temperatures. At T=10 K, it shows a non-Fermi liquid behavior of $\sigma_1(\omega)\sim 1/{\omega}^{\frac 12}$, similar to the case of a ferromagnet SrRuO$_3$. As the temperature ($T$) is increased, on the other hand, $\sigma_1(\omega)$ in the low frequency region is progressively suppressed, deviating from the $1/{\omega}^{\frac 12%}$-dependence. Interestingly, the suppression of $\sigma_1(\omega)$ is found to scale with $\omega /T$ at all temperatures. The origin of the $% \omega /T$ scaling behavior coupled with the non-Fermi liquid behavior is discussed.