Optical conductivity of overdoped cuprate superconductors: Application to La2 -xSrxCuO4
Abstract
We argue that recent measurements on both the superfluid density and the optical conductivity of high-quality La2 -xSrxCuO4 (LSCO) films can be understood almost entirely within the theory of disordered BCS d -wave superconductors. The large scattering rates deduced from experiments are shown to arise predominantly from weak scatterers, probably the Sr dopants out of the CuO2 plane, and correspond to a significant suppression of Tc relative to a pure reference state with the same doping. Our results confirm the "conventional" viewpoint that the overdoped side of the cuprate phase diagram can be viewed as approaching the BCS weak-coupling description of the superconducting state, with significant many-body renormalization of the plasma frequency. They suggest that, while some of the decrease in Tc with overdoping may be due to weakening of the pairing, disorder plays an essential role.
- Publication:
-
Physical Review B
- Pub Date:
- August 2018
- DOI:
- 10.1103/PhysRevB.98.054506
- arXiv:
- arXiv:1802.10198
- Bibcode:
- 2018PhRvB..98e4506L
- Keywords:
-
- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 10 pages, 8 figures: expt data removed from Fig. 5, minor changes to text