Effect of Single Particle Hopping and out of Plane Magnetic Impurity on Coupled Planar Superconductors

TL;DR

This paper investigates how single particle hopping along the c-axis and out-of-plane magnetic impurities affect the superconducting transition temperature in layered superconductors, comparing conventional and interlayer pair tunneling mechanisms.

Contribution

It demonstrates the detrimental effects of c-axis hopping and magnetic impurities on $T_c$, highlighting differences between conventional and Wheatley-Hsu-Anderson mechanisms.

Findings

C-axis hopping reduces $T_c$ in both mechanisms.

Out-of-plane magnetic impurities suppress $T_c$ more in conventional superconductors.

Sharp decrease of $T_c$ observed at higher impurity concentrations in the WHA mechanism.

Abstract

It is shown that the single particle band motion along the $c$ axis is harmful for superconductivity. Variation of $T_c$ with $c$ axis hopping parameter is shown for both the conventional planar superconductors and for interlayer pair tunneling mechanism of Wheatley Hsu and Anderson(WHA).Effect of out of plane magnetic impurity substitution is shown to suppres $T_c$ more for conventional superconductors whereas there is very sharp decrease of $T_c$ in the WHA mechanism at larger concentrations.