Quasi-1-Dimensional Superconductivity in Highly Disordered NbN Nanowires

TL;DR

This study investigates electron transport in highly disordered NbN nanowires, finding that conventional models fit well and suggesting that intrinsic inhomogeneity may not influence their superconducting properties.

Contribution

The paper provides experimental evidence that conventional phase slip models describe NbN nanowires well, challenging the idea that intrinsic inhomogeneity affects their superconductivity.

Findings

Phase slip models fit the R(T) transition curves.

Critical current follows Ginzburg-Landau prediction.

Intrinsic inhomogeneity may not impact resistive properties.

Abstract

The topic of superconductivity in strongly disordered materials has attracted a significant attention. In particular vivid debates are related to the subject of intrinsic spatial inhomogeneity responsible for non-BCS relation between the superconducting gap and the pairing potential. Here we report experimental study of electron transport properties of narrow NbN nanowires with effective cross sections of the order of the debated inhomogeneity scales. We find that conventional models based on phase slip concept provide reasonable fits for the shape of the R(T) transition curve. Temperature dependence of the critical current follows the text-book Ginzburg-Landau prediction for quasi-one-dimensional superconducting channel Ic~(1-T/Tc)^3/2. Hence, one may conclude that the intrinsic electronic inhomogeneity either does not exist in our structures, or, if exist, does not affect their resistive state properties.