Experimental evidence for hotspot and phase-slip mechanisms of voltage switching in ultra-thin YBa2Cu3O7-x nanowires

TL;DR

This study investigates voltage switching in ultra-thin YBa2Cu3O7-x nanowires, revealing two mechanisms—hotspot effects and phase-slip lines—dependent on temperature and nanowire dimensions, supported by experimental data and theoretical models.

Contribution

It provides experimental evidence distinguishing hotspot and phase-slip mechanisms of voltage switching in high-temperature superconductor nanowires, aligning with theoretical predictions.

Findings

Voltage switching mechanisms vary with temperature and nanowire size.

Hotspot-assisted switching agrees with Aslamazov-Larkin model.

Phase-slip lines appear at certain conditions.

Abstract

We have fabricated ultra-thin YBa2Cu3O7-x nanowires with a high critical current density and studied their voltage switching behavior in the 4.2 - 90 K temperature range. A comparison of our experimental data with theoretical models indicates that, depending on the temperature and nanowire cross section, voltage switching originates from two different mechanisms: hotspot-assisted suppression of the edge barrier by the transport current and the appearance of phase-slip lines in the nanowire. Our observation of hotspot-assisted voltage switching is in good quantitative agreement with predictions based on the Aslamazov-Larkin model for an edge barrier in a wide superconducting bridge.