We review here the response of mainly conductor-insulator mixtures just above the percolation threshold (pc) under dc bias. I–V characteristics changes from being linear to nonlinear as the applied bias is increased. Closer a sample is to pc, greater is the nonlinearity. Analysis of nonlinear...

We derive the first dynamic correction to the effective refractive index for a square array of cylinders (of finite or infinite refractive index), subject to a low-frequency incident radiation. This correction also imposes constraints on the wave number region for which the Lorentz-Lorenz...

Fractal nanostructured materials, such as nanocomposites and self-affine thin films, are shown to possess giant optical nonlinearities. The enhancement results from the sub-wavelength localization of dipolar modes and strong local field fluctuations.

The electrical resistance of a percolating medium made of a polymer filled with conductive particles may undergo a steep increase over a narrow temperature range above room temperature. A likely mechanism for the effect is the loss of interparticle contact inducing a weakening of the...