Percolation transition of the vortex lattice and c-axis resistivity in high-temperature superconductors.

We use the three-dimensional Josephson-junction array system as a model for studying the temperature dependence of the {ital c}-axis resistivity of high-temperature superconductors, in the presence of an external magnetic field {ital H} applied in the {ital c} direction. We show that the temperature at which the dissipation becomes different from zero corresponds to a percolation transition of the vortex lattice. In addition, the qualitative features of the resistivity versus temperature curves close to the transition are obtained starting from the geometrical configurations of the vortices. The results apply to the cases {ital H}{ne}0 and {ital H}=0. {copyright} {ital 1996 The American Physical Society.}