Superconductivity in overdoped cuprates can be understood from a BCS perspective!

TL;DR

This paper argues that overdoped cuprate superconductors can be explained using conventional Fermi-liquid and BCS theory, with a crossover from strongly correlated underdoped to weakly correlated overdoped regimes, and attributes some anomalies to disorder effects.

Contribution

It demonstrates that a BCS-based Fermi-liquid approach can describe overdoped cuprates, bridging the gap between unconventional and conventional superconductivity theories.

Findings

Overdoped cuprates exhibit properties consistent with Fermi-liquid behavior.

A crossover from strongly correlated to weakly correlated regimes is proposed.

Disorder effects explain some observed deviations from ideal BCS behavior.

Abstract

We summarize key experimental studies of the low energy properties of overdoped cuprate high temperature superconductors and conclude that a theoretical understanding of the ``essential physics" is achievable in terms of a conventional Fermi-liquid treatment of the normal state, and a BCS mean-field treatment of the (d-wave) superconducting state. For this perspective to be consistent, it is necessary to posit that there is a crossover from a strongly correlated underdoped regime (where a different theoretical perspective is necessary) to the more weakly correlated overdoped regime. It is also necessary to argue that the various observed features of the overdoped materials that are inconsistent with this perspective can be attributed to the expected effects of the intrinsic disorder associated with most of the materials being solid state solutions (alloys). As a test of this idea, we make a series of falsifiable predictions concerning the expected behavior of an ``ideal" (disorder free) overdoped cuprate.