Multifractality and nonlinear diamagnetic susceptibility in a superconducting network at percolation

2014 We have calculated numerically the current distribution of a two-dimensional Josephson junction network in a magnetic field. At the percolation threshold and in the approximation of linear junctions this distribution is multifractal. We have also considered the lowest order nonlinear corrections to the diamagnetic susceptibility. This correction scales with one of the exponents of the multifractal exponents appearing in the linear approximation. The crossover magnetic field at which the nonlinear corrections become important scales with a power law in the susceptibility. The exponent of this power law is given by a combination of multifractal exponents of the linearized approximation. J. Phys. France 49 (1988) 1379-1385 AOÚT 1988,