We have fabricated ultrathin $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{7–x}$ 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.

• Received 24 April 2018
• Revised 18 July 2018

DOI:https://doi.org/10.1103/PhysRevB.98.054505