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

Lyatti M, Wolff M. A., Savenko A., Kruth M., Ferrari S., Poppe U., Pernice W., Dunin-Borkowski R. E., Schuck C.

Abstract

We have fabricated ultrathin 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.