Systematic and causal corrections to the coherent potential approximation

Jarrell, M. ; Krishnamurthy, H. R. (2001) Systematic and causal corrections to the coherent potential approximation Physical Review B, 63 (12). 125102_1-125102_10. ISSN 0163-1829

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Official URL: http://prb.aps.org/abstract/PRB/v63/i12/e125102

Related URL: http://dx.doi.org/10.1103/PhysRevB.63.125102

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 Nc→∞. We use the DCA to study the Anderson model with binary diagonal disorder. It restores sharp features and band tailing in the density-of-states, 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:Article
Source:Copyright of this article belongs to American Physical Society.
ID Code:17521
Deposited On:16 Nov 2010 09:39
Last Modified:17 May 2016 02:08

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