Flux lattice melting and nonlocal electrodynamics inYBa2Cu3O7<

Abstract

Twinned single crystal YBa 2 Cu 3 O 7Ϫ␦ has been investigated by the c-axis transport measurements with eight contacts and Bʈab planes. This experimental geometry allows studies of the vortex velocity correlations both parallel and perpendicular to the applied magnetic field. A flux-line lattice ͑FLL͒ parallel to the ab planes is found to melt into a disentangled vortex liquid, and for Bр2 T, this melting occurs in a moving FLL above the irreversibility line. A nonlocal contribution to the transport properties is also inferred from the results.