Fractional power-law conductivity in SrRuO_3 and its consequences
  We combine the results of terahertz time-domain spectroscopy with far-infrared transmission and reflectivity to obtain the conductivity of SrRuO_3 over an unprecedented continuous range in frequency, allowing us to characterize the approach to zero frequency as a function of temperature. We show that the conductivity follows a simple phenomenological form, with an analytic structure fundamentally different from that predicted by the standard theory of metals. 
J. S. Dodge, C. P. Weber, J. Corson, J. Orenstein (University of   California, Berkeley), Z. Schlesinger (University of Cali...