Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37236962.
- Also identified by DOI 10.1038/s41467-023-38762-5 and PMC identifier 10220041.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Materials tuned to a quantum critical point display universal scaling properties as a function of temperature T and frequency ω. 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 ω-linear dependence of the optical scattering rate. Here, we present and analyze resistivity and optical conductivity of La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> with x = 0.24. We demonstrate ℏω/k<sub>B</sub>T scaling of the optical data over a wide range of frequency and temperature, T-linear resistivity, and optical effective mass proportional to [Formula: see text] corroborating previous specific heat experiments. We show that a T, ω-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.