LOW-ENERGY EXCITATIONS AND NONERGODICITY IN THE COULOMB GLASS

Recent computational methods permit the determination of the low energ y states of fair sized systems of localized interacting particles in r andom media. Making use of such methods, this paper evaluates the natu re of the low-energy excitations of the system, and it's implications on conductivity and on ergodicity. Two- and three-dimensional systems are examined. it is found that the low energy excitations exhibit stro ng correlation effects, indicating that one-particle theories for equi librium and non-equilibrium properties are not justified. Ergodicity i s tested by relaxation at zero temperature. It is found that relaxatio n time can be extremely long, indicating that the system is not ergodi c at low temperatures.