Narrow bridge structures were precisely fabricated (using novel ion-beam-milling techniques) on pulsed-laser-deposited YBa2Cu3O7 films. The bridges have a length scale down to L500. Supercurrents were observed to flow across the bridge structures with critical current densities up to Jc1.3×109 A/cm2, the highest critical current densities yet reported. The current-density magnitudes are consistent with the Onsager-Feynman vortex-ring-creation mechanism (for producing voltages across narrow constrictions) in the length scale region of L, with the coherence length and the London penetration depth. The highest Jc is in good agreement with the critical depairing mechanism.
ASJC Scopus subject areas
- Physics and Astronomy(all)