Spatially Resolved Dynamic Correlation in the Vortex State of High Temperature Superconductors

Abstract

We report transport measurements in the mixed state of ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ single crystals using a contact geometry which enables control of the gradient of the Lorentz force acting on the vortices. The spatial dependence of the vortex velocity profile in the liquid and solid vortex phases is resolved providing information about the transverse dynamic correlation of vortices. While in the liquid phase the vortices respond locally to the driving force, in the solid regime they show long range velocity correlation over macroscopic distances. At high driving force gradients, vortex-vortex shear stresses exceed the elastic limit and the dynamics is characterized by plastic motion.