Role of Interfaces in the Proximity Effect in Anisotropic Superconductors

TL;DR

This study investigates how the interface morphology in YBCO-Co doped YBCO bilayers influences the proximity effect, revealing that interface quality can significantly alter the critical temperature through quasiparticle transmission.

Contribution

It demonstrates the impact of interface morphology on the proximity effect in anisotropic superconductors, providing new insights into controlling superconducting properties.

Findings

Interface morphology affects the coupling between layers.

Critical temperature can be depressed or nearly unchanged.

Quasiparticle transmission explains the observed effects.

Abstract

We report measurements of the critical temperature of YBCO-Co doped YBCO Superconductor-Normal bilayer films. Depending on the morphology of the S-N interface, the coupling between S and N layers can be turned on to depress the critical temperature of S by tens of degrees, or turned down so the layers appear almost totally decoupled. This novel effect can be explained by the mechanism of quasiparticle transmission into an anisotropic superconductor.