COULOMB GAP AT FINITE TEMPERATURES

The Coulomb glass, a model of interacting localized electrons in a random potential, exhibits a soft gap, the Coulomb gap, in the single-particle density of states (DOS) g(epsilon,T) close to the chemical potential mu. In this paper we investigate the Coulomb gap at finite temperatures T by means of a Monte Carlo method. We find that the Coolomb gap fills with increasing temperature. In contrast to previous results the temperature dependence is, however, much stronger than g(mu,T)similar to T-D-1 as predicted analytically It can be described by power laws with the exponents 1,75+/-0.1 for the two-dimensional model and 2.7+/-0.1 for the three-dimensional model. Nevertheless, the relation g(mu,T)similar to g(epsilon,T=0) with \epsilon-mu\=k(B)T seems to be valid, since energy dependence of the DOS at low temperatures has also been found to follow power laws with these exponents.