Critical-Current Reduction in Thin Superconducting Wires Due to Current Crowding

TL;DR

This paper experimentally shows that the critical current in NbTiN superconducting wires decreases due to geometric current-crowding effects, impacting device performance in applications like detectors and amplifiers.

Contribution

It provides experimental evidence linking wire geometry to critical current reduction caused by current crowding in superconducting devices.

Findings

Critical current decreases at corners and expansions

Geometric design influences superconducting performance

Implications for superconducting device optimization

Abstract

We demonstrate experimentally that the critical current in superconducting NbTiN wires is dependent on their geometrical shape, due to current-crowding effects. Geometric patterns such as 90 degree corners and sudden expansions of wire width are shown to result in the reduction of critical currents. The results are relevant for single-photon detectors as well as parametric amplifiers.