Dielectric Response in Strongly Disordered Materials: Analytic Approaches

Abstract

Abstract Interacting dipolar centers at frozen random positions are known to provide a microscopic mechanism for strong non-Debye behavior in the dielectric response. In particular, it has been shown previously by kinetic Monte Carlo simulation that nearly constant dielectric loss spectra emerge from random dipolar lattice gas models. Here we discuss analytic or semi-analytic theories that allow us to treat such complex models that involve structural randomness and electrostatic interactions. After a brief review of a dynamic pair approximation we present a scaling theory which is based on the observation that relaxation of a selected dipole is dominated by the interaction with its closest neighbor. Finally, some first steps in a new, field-theoretic approach are outlined.