Transport velocity in two-dimensional random media.

Abstract

We study the transport properties of a two-dimensional randomly disordered dielectric medium. The medium consists of infinitely long dielectric cylinders with a real dielectric constant ${\mathrm{\ensuremath{\epsilon}}}_{\mathit{a}}$, embedded in a different dielectric medium with ${\mathrm{\ensuremath{\epsilon}}}_{\mathit{b}}$=1. The transport velocity is calclated within the low-density approximation of the Bethe-Salpeter equation and within the coated extension of the well-known coherent-potential approximation for a random arrangement of dielectric cylinders. Results for the long-wavelength effective dielectric constant, phase velocity, and transport velocity are presented for both the s and p polarization of electromagnetic waves. In addition, it is found that localization is achieved more easily for the s than for the p polarization.