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(ε,T) close to the chemical potential µ. In this paper we investigate the Coulomb gap at finite temperatures T by means of a Monte Carlo method. We find that the Coulomb gap fills with increasing temperature. In contrast to previous results the temperature dependence is, however, much stronger than g(µ,T)~TD-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(µ,T)~g(ε,T=0) with |ε - µ| = kBT seems to be valid, since energy dependence of the DOS at low temperatures has also been found to follow power laws with these exponents.
M. Sarvestani et al., "Coulomb Gap at Finite Temperatures," Physical Review B (Condensed Matter), vol. 52, no. 6, pp. R3820 - R3823, American Physical Society (APS), Aug 1995.
The definitive version is available at https://doi.org/10.1103/PhysRevB.52.R3820
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© 1995 American Physical Society (APS), All rights reserved.
01 Aug 1995