Non-Fermi liquid behavior and scaling of low frequency suppression in   optical conductivity spectra of CaRuO$_3$
  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. 
Y. S. Lee, Jaejun Yu, J. S. Lee, T. W. Noh, T.-H. Gimm, Han-Yong Choi,   and C. B. Eom