INFLUENCE OF DISORDER ON THE TRANSPORT-PROPERTIES OF 2-DIMENSIONAL VORTEX LIQUIDS

The dislocation-plasma model is used to study the disorder-induced corrections to the flux-flow resistivity, voltage-current characteristics, and spectrum of the voltage noise for a two-dimensional superconductor in a mixed state above the temperature of the vortex-lattice melting. The correction to the flux-flow resistivity is determined by the density of free dislocations and diverges in the vicinity of the melting temperature according to the exponential law of Nelson and Halperin. The voltage-current dependence contains a characteristic current that does not depend upon the strength of disorder and is totally determined by the Correlation properties of the vortex liquid. The melting temperature and strength of the pinning potential can be extracted from the analysis of the nonlinear behavior in the liquid phase.