J. Phys. IV France
Volume 114, April 2004
Page(s) 677 - 678

J. Phys. IV France
114 (2004) 677
DOI: 10.1051/jp4:2004114162

Low-temperature d.c. transport in anisotropic dirty thin dielectric films

S. Teber

William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA

A theory of low-temperature ohmic dc transport in dirty 2D quasi-one dimensional electronic crystals, such as charge-density wave (CDWs) thin films, is presented. At low temperatures we find that Efros-Shklovskii (ES) variable-range hopping (VRH) laws dominate the transport. At the lowest energies of the problem we find a usual impurity-independent linear Coulomb-gap (CG), $g(\epsilon)
\propto \epsilon$ , in the single particle density of states. An ES law for the resistivity follows with the usual exponent 1/2: $\rho \propto \exp[(T_{ES}/T)^{1/2}]$, but with TES increasing with disorder. At higher energies, the peculiar screening of the interactions leads to a crossover to an unusual CG which is quadratic, $g(\epsilon) \propto \epsilon^2$, for a 2D system and impurity dependent. This leads to a temperature crossover to an unusual ES law $\rho \propto
\exp[(T_{3/5}/T)^{3/5}]$ , with T3/5 increasing with disorder. At even higher temperatures a crossover to activation takes place. The results should apply to mono-layers of 4kF CDWs. Key words. Variable-range hopping - 4kF charge-density wave.

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