Peculiarities of the resistive transition in fractal superconducting structures

The influence of fractal clusters of a normal phase on the current-voltage characteristics of a percolation superconductor in the region of a resistive transition has been studied. The clusters represent the aggregates of columnar defects, which give rise to a correlated microscopic disorder in the system. Dependencies of the static and dynamic resistance on the transport current are obtained for an arbitrary fractal dimension of the cluster boundaries. It is revealed that a mixed state of the vortex glass type is realized in the superconducting system involved.