Experiments on linear and nonlinear wave propagation in periodic media

Abstract

Recently, there has been interest in linear and nonlinear wave propagation in periodic and random potential fields. Studies of such effects using surface waves in adsorbed superfluid helium, which should show strong local nonlinear behavior, have begun. While there has been considerable theoretical attention given to nonlinear effects for these waves, there have been no systematic experimental studies. Research with a variety of experiments, including studies of linear and nonlinear propagation of these waves in uniform as well as periodic one-dimensional media, has begun. Measurements have been made with drive levels varying over five orders of magnitude. The results have been found to exhibit nonlinear effects including a velocity of propagation dependent on drive level. [Work supported by NSF DMR 9000549 and the Office of Naval Research.]