Self-energy-functional approach: Analytical results and the Mott-Hubbard transition

dc.creatorPotthoff, M.
dc.date2003-06-11
dc.date2003-11-20
dc.date.accessioned2026-07-07T02:51:46Z
dc.date.available2026-07-07T02:51:46Z
dc.descriptionThe self-energy-functional approach proposed recently is applied to the single-band Hubbard model at half-filling to study the Mott-Hubbard metal-insulator transition within the most simple but non-trivial approximation. This leads to a mean-field approach which is interesting conceptually: Trial self-energies from a two-site single-impurity Anderson model are used to evaluate an exact and general variational principle. While this restriction of the domain of the functional represents a strong approximation, the approach is still thermodynamically consistent by construction and represents a conceptual improvement of the ``linearized DMFT'' which has been suggested previously as a handy approach to study the critical regime close to the transition. It turns out that the two-site approximation is able to reproduce the complete (zero and finite-temperature) phase diagram for the Mott transition. For the critical point at T=0, the entire calculation can be done analytically. This calculation elucidates different general aspects of the self-energy-functional theory. Furthermore, it is shown how to deal with a number of technical difficulties which appear when the self-energy functional is evaluated in practice.
dc.description14 pages, final version including finite-temperature results and phase diagram, accepted by EPJB
dc.identifierhttps://arxiv.org/abs/cond-mat/0306278
dc.identifierhttp://arxiv.org/abs/cond-mat/0306278
dc.identifierEur. Phys. J. B 36, 335 (2003)
dc.identifierdoi:10.1140/epjb/e2003-00352-7
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/21592
dc.subjectStrongly Correlated Electrons
dc.subjectSuperconductivity
dc.titleSelf-energy-functional approach: Analytical results and the Mott-Hubbard transition
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