title: ac Hopping conduction at extreme disorder takes place on the percolating cluster.
abstract: Simulations of the random barrier model show that ac currents at extreme disorder are carried almost entirely by the percolating cluster slightly above threshold; thus contributions from isolated low-activation-energy clusters are negligible. The effective medium approximation in conjunction with the Alexander-Orbach conjecture lead to an excellent analytical fit to the universal ac conductivity with no nontrivial fitting parameters.
authors.affiliation: DNRF Centre Glass and Time, IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Schrøder
authors.forename: Jeppe C
authors.initials: JC
authors.lastname: Dyre