Geometry-induced reduction of the critical current in superconducting nanowires

TL;DR

This study investigates how geometric bends in superconducting NbN nanowires reduce their critical current, revealing that actual reductions are less severe than theoretical models predict, especially at lower temperatures.

Contribution

The paper provides experimental evidence that geometric bends cause less critical current reduction than London and Ginsburg-Landau models suggest, particularly at low temperatures.

Findings

Critical current reduction is less than predicted by models.

Bends mainly affect critical current at low temperatures.

Experimental results differ from theoretical expectations.

Abstract

Reduction of the critical current in narrow superconducting NbN lines with sharp and rounded bends with respect to the critical current in straight lines was studied at different temperatures. We compare our experimental results with the reduction expected in the framework of the London model and the Ginsburg-Landau model. We have experimentally found that the reduction is significantly less than either model predicts. We also show that in our NbN lines the bends mostly contribute to the reduction of the critical current at temperatures well below the superconducting transition temperature.