Effect of nonmagnetic and magnetic impurities on the specific heat jump in anisotropic superconductors

TL;DR

This paper investigates how nonmagnetic and magnetic impurities affect the specific heat jump at the critical temperature in anisotropic superconductors, revealing significant changes due to spin-flip scatterers.

Contribution

It provides a theoretical analysis of impurity effects on specific heat jump in anisotropic superconductors, highlighting the impact of spin-flip scatterers on $\Delta C$ versus $T_c$ dependence.

Findings

Spin-flip scatterers drastically alter $\Delta C$-$T_c$ dependence.

Even small amounts of magnetic impurities have significant effects.

Implications for identifying s-wave admixture in high-$T_c$ superconductors.

Abstract

The specific-heat jump $\Delta C$ at a critical temperature $T_c$ in an anisotropic superconductor containing both potential and spin-flip scatterers is calculated within a weak-coupling mean-field approximation. It is shown that the presence of even a small amount of spin-flip scatterers in the sample leads to a drastic change in the dependence of $\Delta C$ on $T_c$ in a disordered $(d+s)$-wave or a strongly anisotropic s-wave superconductor. The implications for experimental tests for the presence of an s-wave admixture in the superconducting order parameter of high-$T_c$ superconductors are discussed.