Strong correlations generically protect d-wave superconductivity against disorder

TL;DR

Strong electronic correlations near a Mott insulator significantly suppress pair-breaking and transport scattering rates in d-wave superconductors, explaining their robustness against non-magnetic impurities.

Contribution

The paper demonstrates that strong correlations inherently protect d-wave superconductivity from impurity effects, a novel insight into high-Tc superconductor resilience.

Findings

Correlation effects suppress scattering rates near Mott insulators

Forward scattering amplitude is enhanced by correlations

d-wave superconductors are robust against non-magnetic impurities

Abstract

We address the question of why strongly correlated d-wave superconductors, such as the cuprates, prove to be surprisingly robust against the introduction of non-magnetic impurities. We show that, very generally, both the pair-breaking and the normal state transport scattering rates are significantly suppressed by strong correlations effects arising in the proximity to a Mott insulating state. We also show that the correlation-renormalized scattering amplitude is generically enhanced in the forward direction, an effect which was previously often ascribed to the specific scattering by charged impurities outside the copper-oxide planes.