Current-voltage characteristics of quasi-one-dimensional superconductors: An S-curve in the constant voltage regime

TL;DR

This paper investigates the current-voltage behavior of superconducting nanowires under constant voltage, revealing an unusual S-shaped IV characteristic caused by the dynamics of the superconducting state and two critical currents.

Contribution

It introduces a novel understanding of the S-curve IV characteristic in quasi-one-dimensional superconductors due to the interplay of two critical currents.

Findings

IV characteristic exhibits an S-shape under constant voltage

Existence of two critical currents j_{c1} and j_{c2} affecting stability

The phase slip state occurs at j_{c1}

Abstract

Applying a constant voltage to superconducting nanowires we find that its IV-characteristic exhibits an unusual S-behavior. This behavior is the direct consequence of the dynamics of the superconducting condensate and of the existence of two different critical currents: j_{c2} at which the pure superconducting state becomes unstable and j_{c1}<j_{c2} at which the phase slip state is realized in the system.