EXPERIMENTAL-EVIDENCE OF A NONLOCAL RESISTIVITY IN A VORTEX LINE LIQUID

We present transport measurements on YBCO single crystals in the vorte x liquid regime using the DC flux transformer geometry. We show that t he data are inconsistent with the material being an anisotropic, local conductor. The results provided evidence for non-local transport whic h indicate that there can be correlated vortex motion over macroscopic distances in this system. We have shown that this correlated vortex m otion can be destroyed by either thermal fluctuations or the applicati ons of large driving forces.