Two-component Coulomb glass in insulators with a local attraction

Joe Mitchell, Anirban Gangopadhyay, Victor Galitski, Markus Müller

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7 Citations (Scopus)

Abstract

Motivated by evidence of local electron-electron attraction in experiments on disordered insulating films, we propose a two-component Coulomb glass model that combines strong disorder and long-range Coulomb repulsion with the additional possibility of local pockets of a short-range interelectron attraction. This model hosts a variety of interesting phenomena, in particular a crucial modification of the Coulomb gap previously believed to be universal. Tuning the short-range interaction to be repulsive, we find nonmonotonic humps in the density of states within the Coulomb gap. We further study variable-range hopping transport in such systems by extending the standard resistor network approach to include the motion of both single electrons and local pairs. In certain parameter regimes the competition between these two types of carriers results in a distinct peak in resistance as a function of the local attraction strength, which can be tuned by a magnetic field.

Original languageEnglish
Article number195141
JournalPhysical Review B
Volume85
Issue number19
DOIs
Publication statusPublished - 25 May 2012
Externally publishedYes

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