Dielectric susceptibility of the Coulomb-glass

Abstract

We derive a microscopic expression for the dielectric susceptibility $χ$ of a Coulomb glass, which corresponds to the definition used in classical electrodynamics, the derivative of the polarization with respect to the electric field. The fluctuation-dissipation theorem tells us that $χ$ is a function of the thermal fluctuations of the dipole moment of the system. We calculate $χ$ numerically for three-dimensional Coulomb glasses as a function of temperature and frequency.