Systematic and causal corrections to the coherent potential approximation

Jarrell, M and Krishnamurthy, HR (2001) Systematic and causal corrections to the coherent potential approximation. In: Physical Review B, 63 (12). pp. 5102-1.

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Abstract

The dynamical cluster approximation (DCA) is modified to include disorder. The DCA incorporates nonlocal corrections to local approximations such as the coherent potential approximation (CPA) by mapping the lattice problem with disorder, and in the thermodynamic Limit, to a self-consistently embedded finite-sized cluster problem. It satisfies all of the characteristics of a successful cluster approximation. It is causal, preserves the point-group and translational symmetry of the original lattice, recovers the CPA when the cluster size equals one, and becomes exact as N-c-->infinity. We use the DCA to study the Anderson model with binary diagonal disorder. It restores sharp features and band tailing in the density-of-stales, which reflect correlations in the local environment of each site. While the DCA does not describe the localization transition, it does describe precursor effects of localization.

Item Type:	Journal Article
Publication:	Physical Review B
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society.
Keywords:	High Dimensions;Localization;Symmetry;Model
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	04 Feb 2010 05:06
Last Modified:	19 Sep 2010 04:56
URI:	http://eprints.iisc.ac.in/id/eprint/17402

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