Critical conducting networks in disordered solids: ac universality from topological arguments - art. no. 212203

This paper advocates an unconventional description of charge transport proc esses in disordered solids, which brings together the ideas of fractal geom etry, percolation theory, and topology of manifolds. We demonstrate that th e basic features of ac conductivity in disordered materials as seen in vari ous experiments are reproduced with remarkable accuracy by the conduction p roperties of percolating fractal networks near the threshold of percolation . The universal character of ac conductivity in three embedding dimensions is discussed in connection with the available experimental data. An importa nt prediction of the present model is the "hyperuniversal" scaling sigma(om ega)proportional to omega (1/3) for ac conduction in two dimensions.