Can Impurity Effects Help to Identify the Symmetry of the Order Parameter of the Cuprates?

TL;DR

This paper explores how non-magnetic impurities influence superconductors with different order parameter symmetries, highlighting how impurity effects can distinguish between d-wave and anisotropic s-wave symmetries.

Contribution

It provides a comparative analysis of impurity effects on d_{x^2 - y^2} and anisotropic s-wave superconductors, proposing impurity effects as a tool to identify order parameter symmetry.

Findings

Impurity effects differ significantly between d-wave and anisotropic s-wave superconductors.

The phase of the order parameter influences impurity-induced changes.

Impurity effects can serve as indicators of the underlying symmetry of the superconducting gap.

Abstract

The effects of non-magnetic impurities on the properties of superconductors with order parameters (OP) of different symmetry are discussed. In particular, we contrast the case of a d_{x^2 - y^2} with various forms of an anisotropic s-wave (ASW) gap. The biggest qualitative difference occurs if the phase of the s-wave OP does not change sign.