Predictions for Impurity-Induced Tc Suppression in the High-Temperature Superconductors

TL;DR

This paper investigates how impurity scattering affects the critical temperature in high-temperature cuprate superconductors, using numerical and analytical methods to understand the relationship and implications for the order parameter symmetry.

Contribution

It provides a universal model for Tc suppression due to impurities in d-wave superconductors, aiding in determining the order parameter symmetry in cuprates.

Findings

Tc depends universally on residual resistivity regardless of microscopic details

Impurity scattering effects are analyzed within strong-coupling Eliashberg framework

Results support the use of resistivity measurements to infer pairing symmetry

Abstract

We address the question of whether anisotropic superconductivity is compatible with the evidently weak sensitivity of the critical temperature Tc to sample quality in the high-Tc copper oxides. We examine this issue quantitatively by solving the strong-coupling Eliashberg equations numerically as well as analytically for s-wave impurity scattering within the second Born approximation. For pairing interactions with a characteristically low energy scale, we find an approximately universal dependence of the d-wave superconducting transition temperature on the planar residual resistivity which is independent of the details of the microscopic pairing. These results, in conjunction with future systematic experiments, should help elucidate the symmetry of the order parameter in the cuprates.