Insulation breakdown in a random nonpercolating network of conductors

Abstract

For a non percolating network of conductors, the insulation breakdown voltage V_B vanishes near c_c, the percolation threshold for conductors, as (c_c-c)^t'. Using a small-cell real-space renormalisation group technique (with scale factor b up to 3) the authors find t' approximately=0.9 for d=2. A Monte Carlo estimate for 20*20 square (bond-diluted) and triangular (site-diluted) lattices gives t'=0.8+or-0.1. The breakdown universality classes for such metal-insulator transition are also discussed.