Critical current in Nb-Cu-Nb junctions with non-ideal interfaces

TL;DR

This paper experimentally investigates the critical current behavior in Nb-Cu-Nb Josephson junctions with non-ideal interfaces, analyzing how it varies with thickness and temperature, and compares results with theoretical models.

Contribution

It provides the first comprehensive experimental analysis of critical currents in Nb-Cu-Nb junctions with dirty interfaces, validating theoretical predictions without fitting parameters.

Findings

Critical current decays with increasing thickness and temperature.

Experimental data aligns well with theoretical calculations.

Interfaces are characterized as 'dirty', affecting junction behavior.

Abstract

We report on experimental studies of superconductor (Nb) - normal metal (Cu) - superconductor (Nb) junctions with dirty interfaces between the different materials. By using a set of simultaneously prepared samples, we investigated the thickness dependence as well as the temperature dependence of the critical currents in the junctions. Good agreement between the decay of the measured critical currents and theoretical calculations was obtained without any fitting parameters.