NONEQUILIBRIUM DIELECTRIC BEHAVIOR IN GLASSES AT LOW-TEMPERATURES - EVIDENCE FOR INTERACTING DEFECTS

We find that recent low-temperature nonequilibrium dielectric experime nts indicate that glasses have strongly interacting defects. While man y of the features found in the experiments can be explained by the sta ndard model of noninteracting two-level systems, we find that the freq uency dependence cannot. Using a Monte Carlo simulation of a nearest-n eighbor Ising spin glass, we show that interactions between defects ca n qualitatively explain the experiments because they lead to the forma tion of clusters and a hole in the distribution of local fields.