Critical exponents of percolating wire networks

Measurements of electronic and magnetic properties of percolating, aluminum wire networks are presented and compared with numerical and analytic results. As opposed to vapor-deposited films, these networks are well suited for comparison to theory of two-dimensional percolation since they are exact replicas of models used to study percolation. We find that the ratio of the exponents for the conductivity and the percolation length, t=0.980.03, is consistent with recent computer studies but not with the Alexander-Orbach conjecture. The critical current exponent, within error, is given by v==43. Finally, the critical field exponent is given by k=1.110.04, consistent with our prediction of k=1.15 as well as with numerical studies.