User:Nils Blümer/Dynamical mean-field theory

Todo list

 * Collect issues with the current DMFT entry in the main Wikipedia
 * Revise introductory 3 paragraphs locally
 * Feed revised introduction into main Wikipedia
 * Identify next small target

List of issues with DMFT article in main Wikipedia
cf. Talk:Dynamical mean field theory
 * bias (specify!)
 * incorrect characterization of EDMFT
 * missing hyphen in topic name (mean-field)

Current (old) introduction
Dynamical mean-field theory (DMFT) is a method to determine the electronic structure of strongly correlated materials. In such materials, the approximation of independent electrons, which is used in density functional theory and usual band structure calculations, breaks down. Dynamical Mean-Field Theory, a non-perturbative treatment of local interactions between electrons, bridges the gap between the nearly free electron gas limit and the atomic limit of condensed-matter physics.

DMFT consists in mapping a many-body lattice problem to a many-body local problem, called an impurity model. While the lattice problem is in general intractable, the impurity model is usually solvable through various schemes. The mapping in itself does not constitute an approximation. The only approximation made in ordinary DMFT schemes is to assume the lattice self-energy to be a momentum-independent (local) quantity. This approximation becomes exact in the limit of lattices with an infinite coordination.

One of DMFT's main successes is to describe the phase transition between a metal and a Mott insulator when the strength of electronic correlations is increased. It has been successfully applied to real materials, in combination with the local density approximation of density functional theory.

Working copy of introduction
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