Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat

Materials tuned to a quantum critical point display universal scaling properties as a function of temperature T and frequency omega.A long-standing puzzle regarding cuprate superconductors has been the observed power-law dependence of optical conductivity with an exponent smaller than one, in contrast to T-linear dependence of the resistivity and.-linear dependence of the optical scattering rate. Here, we present and analyze resistivity and optical conductivity of La2-xSrxCuO4 with x = 0.24. We demonstrate h omega/k(B)T scaling of the optical data over a wide range of frequency and temperature, T-linear resistivity, and optical effective mass proportional to similar to in T corroborating previous specific heat experiments. We show that a T, omega-linear scaling Ansatz for the inelastic scattering rate leads to a unified theoretical description of the experimental data, including the power-law of the optical conductivity. This theoretical framework provides new opportunities for describing the unique properties of quantum critical matter.

Automated summary

In this paper, researchers experimentally demonstrated the universal scaling properties of resistivity, optical conductivity, and optical effective mass of La2-xSrxCuO4 as a function of frequency and temperature. They also proposed a new theoretical framework to describe the unique properties of quantum critical matter.