Universal temperature dependence of the conductivity of a strongly disordered granular metal
A. R. Akhmerov, A. S. Ioselevich
L.D. Landau Institute for Theoretical Physics, 119334 Moscow, Russia
PACS: 72.80.Tm, 73.50.-h, 73.63.-b
Abstract
A disordered array of metal grains with large and
random intergrain conductances is studied within the one-loop
accuracy renormalization group approach. While at low level of
disorder the dependence of conductivity on is
nonuniversal (it depends on details of the array's geometry), for
strong disorder this dependence is described by a
universal nonlinear function, which depends only on the array's
dimensionality. In two dimensions this function is found
numerically. The dimensional crossover in granular films is
discussed.