Europhys. Lett.
Volume 62, Number 5, June 2003
Page(s) 705 - 711
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 May 2003
DOI: 10.1209/epl/i2003-00430-0
Europhys. Lett., 62 (5) , pp. 705-711 (2003)

Coulomb ordering of Anderson-localized electron systems

A. A. Slutskin1, M. Pepper2 and H. A. Kovtun1

1  B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
2  Cavendish Laboratory, University of Cambridge Madingley Road, Cambridge CB3 0HE, UK

(Received 16 January 2003; accepted in final form 19 March 2003)

We study the influence of interelectron Coulomb repulsion on an electron system undergoing strong Anderson localization. It is shown that at sufficiently low electron densities and for the system dimension >1, the Coulomb forces order the localized electrons into a slightly and randomly distorted crystal lattice. This Coulomb ordered Anderson localized electron state (COALES) is beyond the conventional Coulomb glass concept. The weak residual disorder inherent to the COALES is found to cause an infinite multi-valley degeneracy of the ground state similar to that in the spin glass. With increasing electron density the COALES turns into the Coulomb glass or into a different electron crystal-like structure, depending on parameters of the random potential localizing the electrons.

71.45.-d - Collective effects.
72.15.Rn - Localization effects (Anderson or weak localization).
73.20.-r - Electron states at surfaces and interfaces.

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