Scaling properties of the optical conductivity of Bi-based cuprates

TL;DR

This study investigates the optical conductivity of Bi-based cuprates, revealing a universal scaling behavior with a temperature-dependent scattering rate that is frequency-independent, enhancing understanding of high-temperature superconductivity.

Contribution

It demonstrates a universal scaling function for optical conductivity in Bi2Sr2Ca2Cu3O10, including a temperature-independent background and T-squared correction, advancing the analysis of superconducting properties.

Findings

Successful collapse of experimental data onto a universal scaling function

Identification of a linear temperature-dependent scattering rate

Observation of a frequency-independent scattering rate

Abstract

We present novel infrared optical conductivity data on the three layer high Tc superconductor Bi2Sr2Ca2Cu3O10 at optimal doping. We extend the analysis of an earlier publication, providing a universal scaling function sigma(omega,T)=g(omega/T)/T for the optical conductivity. In the present manuscript we obtain a good scaling collapse of the experimental curves on the g(omega/T) over a wide range of values of omega/T (at least in range 0 to 10), if we assume that g(omega/T) is superimposed on a non-universal background which is temperature independent. We obtain the same result, if in our analysis we allow this background to have a T-squared temperature dependent correction. The most striking property of g(omega/T) is, that it corresponds to a scattering rate which varies linearly as a function of temperature, but which is independent of the frequency.