2001/08/28 by Lorenz Bartosch, L. Bartosch, Peter Kopietz +1 · 2 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Organic and Molecular Conductors Research #Quantum and electron transport phenomena #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1140/epjb/e2002-00210-2
published as Eur. Phys. J. B 28, 29 (2002). · 6 pages, 4 figures
arxiv created 2001/08/28 · openalex publication_date 2002/07/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We consider the effect of Coulomb interactions on the average density of states (DOS) of disordered low-dimensional metals for temperatures T and frequencies omega smaller than the inverse elastic life-time. Using the fact that long-range Coulomb interactions in two dimensions (2d) generate ln2-singularities in the DOS nu (omega) but only ln-singularities in the conductivity sigma(omega), we can re-sum the most singular contributions to the average DOS via a simple gauge-transformation. If limomega -> 0 sigma (omega) > 0, then a metallic Coulomb gap nu(omega) propto |omega|/e4 appears in the DOS at T=0 for frequencies below a certain crossover frequency Omega2 which depends on the value of the DC conductivity sigma(0). Here, -e is the charge of the electron. Naively adopting the same procedure to calculate the DOS in quasi 1d metals, we find nu(omega) propto (|omega|/Omega1)1/2 exp(-Omega1/|omega|) at T = 0, where Omega1 is some interaction-dependent frequency scale. However, we argue that in quasi 1d the above gauge-transformation method is on less firm grounds than in 2d. We also discuss the behavior of the DOS at finite temperatures and give numerical results for the expected tunneling conductance that can be compared with experiments.