Non-Fermi liquid behavior of SrRuO_3 -- evidence from infrared conductivity

TL;DR

This study investigates the infrared conductivity of SrRuO_3, revealing non-Fermi liquid behavior characterized by unusual frequency dependence of conductivity and temperature effects, challenging traditional metallic models.

Contribution

It provides experimental evidence of non-Fermi liquid charge dynamics in SrRuO_3 through detailed infrared conductivity measurements.

Findings

Conductivity decreases as ^{-1/2} at low temperatures.

Conductivity increases in the far-infrared at high temperatures.

Charge dynamics differ significantly from Fermi-liquid metals.

Abstract

The reflectivity of the itinerant ferromagnet SrRuO_3 has been measured between 50 and 25,000 cm-1 at temperatures ranging from 40 to 300 K, and used to obtain conductivity, scattering rate, and effective mass as a function of frequency and temperature. We find that at low temperatures the conductivity falls unusually slowly as a function of frequency (proportional to \omega^{-1/2}), and at high temperatures it even appears to increase as a function of frequency in the far-infrared limit. The data suggest that the charge dynamics of SrRuO_3 are substantially different from those of Fermi-liquid metals.