Multiterminal transport measurements indicating a strongly correlated vortex liquid above the first order melting transition in untwinned ${\mathrm{YBa}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ single crystals are presented. The correlation is found to be surprisingly stable for different weak variations of point disorder. We investigate the differences between intervortex and intravortex correlations in different contact geometries. The results are in agreement with the local conductivity model, with zero resistivity along straight vortex line segments.

• Received 18 September 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.1873