Comment on the anisotropic impurity scattering in superconductors

TL;DR

This paper clarifies that strong anisotropic impurity scattering in superconductors generally suppresses the critical temperature, countering previous suggestions of possible enhancement, and emphasizes the role of impurity potential symmetry.

Contribution

It revises earlier claims by analyzing anisotropic impurity scattering effects, demonstrating the consistent decrease of critical temperature with impurity rate for certain potential symmetries.

Findings

Critical temperature decreases with impurity scattering rate.

Anisotropic impurity potential symmetry influences superconducting properties.

Reconciliation of previous claims with established disorder effects.

Abstract

We discuss a case of a strong anisotropic impurity scattering within the model introduced in our previous paper [Phys. Rev. B54, 15463 (1996)] and clarify our former statement about a possible enhancement of the critical temperature in this scattering regime. We show that for the anisotropy of the impurity potential determined by the functions from the non-identity irreducible representations of the crystal point group, the critical temperature decreases with the impurity scattering rate which is consistent with a generally understood role of disorder in superconductors.