Giant dispersion of critical currents in superconductor with fractal clusters of a normal phase

TL;DR

This paper investigates how fractal-shaped normal phase clusters in superconductors affect flux dynamics, revealing conditions for giant critical current dispersion and potential for enhanced current-carrying capacity.

Contribution

It introduces a model for critical current distribution in fractal superconductors and identifies the fractal dimension range where critical current dispersion becomes infinite.

Findings

Critical current dispersion becomes infinite at certain fractal dimensions.

Fractality of clusters increases the superconductor's critical current.

Maximum current capacity aligns with giant dispersion regions.

Abstract

The influence of fractal clusters of a normal phase on the dynamics of a magnetic flux trapped in a percolative superconductor is considered. The critical current distribution and the current-voltage characteristics of fractal superconducting structures in the resistive state are obtained for an arbitrary fractal dimension of the cluster boundaries. The range of fractal dimensions, where the dispersion of critical currents becomes infinite, is found. It is revealed that the fractality of clusters depresses of the electric field caused by the magnetic flux motion thus increasing the critical current value. It is expected that the maximum current-carrying capability of a superconductor can be achieved in the region of giant dispersion of critical currents.