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Coulomb Gap in the Density of States of Disordered Metals in Two Dimensions

Peter Kopietz
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Abstract

We calculate the effect of Coulomb interactions on the average density of states nu (omega) of two-dimensional disordered electrons. It is shown that for weak disorder the most singular terms in the perturbative expansion of nu (omega) can be summed by means of a simple gauge transformation, which also establishes a relation between the low-frequency behavior of nu (omega) and the average conductivity sigma (omega). Using this relation, we show that if lim_{omega rightarrow 0} sigma (omega) is finite, then nu (omega) approaches C | omega | / e^4 for omega rightarrow 0, where C is a dimensionless constant and e is the charge of the electron. This implies that a normal metallic state of disordered electrons in two dimensions is not a Fermi liquid.

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Peter Kopietz. 1998-07-31. Coulomb Gap in the Density of States of Disordered Metals in Two Dimensions. https://doi.org/10.1103/physrevlett.81.2120

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