Double exchange model for correlated electrons in systems with $t_{2g}$ orbital degeneracy

dc.creatorWohlfeld, Krzysztof
dc.date2006-04-15
dc.date.accessioned2026-07-07T08:05:31Z
dc.date.available2026-07-07T08:05:31Z
dc.descriptionWe formulate the double exchange (DE) model for systems with $t_{2g}$ orbital degeneracy, relevant for hole-doped cubic vanadates. In the relevant regime of strong on-site Coulomb repulsion $U$ we solve the model using two distinct mean-field approximations: Hartree-Fock, and mean-field applied to the formulation of the model in the Kotliar-Ruckenstein slave boson representation. We show how, due to the relative weakness of the DE mechanism via $t_{2g}$ degenerate orbitals, the anisotropic C-type antiferromagnetic metallic phase and the orbital liquid state can be stabilized. This is contrasted with the DE mechanism via $e_g$ degenerate orbitals which stabilizes the ferromagnetic order in the hole-doped regime of manganites. The obtained results are in striking agreement with the observed magnetic structures and the collapse of the orbital order in the doped La$_{1-x}$Sr$_x$VO$_3$, Pr$_{1-x}$Ca$_x$VO$_3$ and Nd$_{1-x}$Sr$_x$VO$_3$.
dc.description10 pages, 2 figures; to appear in: Lectures on the Physics of Highly Correlated Electron Systems X, AIP (2006); this is a more introductory and thorough version of cond-mat/0604384 with (in addition) solutions of the model within Hartree-Fock approximation being discussed
dc.identifierhttps://arxiv.org/abs/cond-mat/0604385
dc.identifierhttp://arxiv.org/abs/cond-mat/0604385
dc.identifierLectures on the Physics of Highly Correlated Electron Systems X, eds. F. Mancini and A. Avella, AIP Conference Proceedings Vol. 846, 295-303, New York 2006.
dc.identifierdoi:10.1063/1.2222278
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/130303
dc.subjectStrongly Correlated Electrons
dc.titleDouble exchange model for correlated electrons in systems with $t_{2g}$ orbital degeneracy
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