{ "id": "2109.04723", "version": "v1", "published": "2021-09-10T08:10:28.000Z", "updated": "2021-09-10T08:10:28.000Z", "title": "Dynamical Mean-Field Theory of Disordered Electrons: Coherent Potential Approximation and Beyond", "authors": [ "Václav Janiš" ], "comment": "30 pages, Lecture Notes for the Autumn School on Correlated Electrons: The Physics of Correlated Insulators, Metals, and Superconductors, 25-29 September 2017, Forschungszentrum J\\\"ulich (https://www.cond-mat.de/events/correl17/)", "categories": [ "cond-mat.dis-nn", "cond-mat.str-el" ], "abstract": "I review the quantum theory of the electron moving in a random environment. First, the quantum mechanics of individual particles scattered on a random potential is discussed. The quantum-mechanical description is extended to many-body systems by using many-body Green functions. The many-body approach is used to derive the coherent-potential approximation and to show how it fits into the dynamical mean-field theory. The generating functional of the coherent-potential approximation is obtained in an analytic form from the limit to infinite dimensions of the general many-body description of non-interacting electrons in random lattices. The analytic generating functional of the mean-field description of random systems is extended to the Falicov-Kimball model with thermally equilibrated scattering lattice potential. The many-body Green functions are then used to calculate transport properties. The electrical conductivity of the coherent-potential approximation is derived from the two-particle Green function calculated in infinite spatial dimensions. Finally, a perturbation theory for the vertex corrections to the mean-field conductivity is introduced. In particular, it is shown how to make the expansion beyond the local approximations conserving.", "revisions": [ { "version": "v1", "updated": "2021-09-10T08:10:28.000Z" } ], "analyses": { "keywords": [ "dynamical mean-field theory", "coherent potential approximation", "disordered electrons", "equilibrated scattering lattice potential", "many-body green functions" ], "tags": [ "lecture notes" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }