Evanescent states and non-equilibrium in driven superconducting nanowires

TL;DR

This paper investigates the non-equilibrium behavior of superconducting nanowires under bias, revealing two distinct superconducting states through theoretical and experimental analysis using tunneling and transport measurements.

Contribution

It introduces the concept of global and bimodal superconducting states in driven nanowires and demonstrates their identification via combined measurement techniques.

Findings

Existence of two different superconducting states under non-equilibrium conditions

Experimental validation of the global and bimodal states

Analysis based on quasiclassical kinetic equations

Abstract

We study the non linear response of current-transport in a superconducting diffusive nanowire between normal reservoirs. We demonstrate theoretically and experimentally the existence of two different superconducting states appearing when the wire is driven out of equilibrium by an applied bias, called global and bimodal superconducting state. The different states are identified by using two probe measurements of the wire, and measurements of the local density of states with tunneling probes. The analysis is performed within the framework of the quasiclassical kinetic equations for diffusive superconductors.