Dynamical mean-field theory

Dynamical mean-field theory (DMFT) is a method to determine the electronic structure of <a href="/facts/Strongly_correlated_materials/PW0DDGyP">strongly correlated materials</a>. In such materials, the approximation of independent electrons, which is used in <a href="/facts/Density_functional_theory/wwz4Gqdg">density functional theory</a> and usual <a href="/facts/Band_structure/W5o7oE2R">band structure</a> calculations, breaks down. Dynamical mean-field theory, a non-perturbative treatment of local interactions between electrons, bridges the gap between the <a href="/facts/Nearly_free_electron_model/fkV4MM5H">nearly free electron</a> gas limit and the atomic limit of <a href="/facts/Condensed-matter_physics/EBVI5nmL">condensed-matter physics</a>.
DMFT consists in mapping a <a href="/facts/Many-body_problem/n2rIxgwv">many-body</a> 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 <a href="/facts/Self-energy/qhFMapN6">self-energy</a> to be a momentum-independent (local) quantity. This approximation becomes exact in the limit of lattices with an infinite <a href="/facts/Coordination_number/mf48hsoX">coordination</a>.
One of DMFT's main successes is to describe the <a href="/facts/Phase_transition/eLP2BY8R">phase transition</a> between a metal and a <a href="/facts/Mott_insulator/nPswoaFc">Mott insulator</a> when the strength of <a href="/facts/Electronic_correlation/1XpBFce2">electronic correlations</a> is increased. It has been successfully applied to real materials, in combination with the <a href="/facts/Local_density_approximation/zJzL3tMF">local density approximation</a> of density functional theory.

Dynamical mean-field theory open-in-new

Dynamical mean-field theory