Random dispersion approximation for the Hubbard model

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dc.creatorEjima, S.
dc.creatorGebhard, F.
dc.creatorNoack, R. M.
dc.date2008-11-26
dc.date.accessioned2026-07-07T12:04:30Z
dc.date.available2026-07-07T12:04:30Z
dc.descriptionWe use the Random Dispersion Approximation (RDA) to study the Mott-Hubbard transition in the Hubbard model at half band filling. The RDA becomes exact for the Hubbard model in infinite dimensions. We implement the RDA on finite chains and employ the Lanczos exact diagonalization method in real space to calculate the ground-state energy, the average double occupancy, the charge gap, the momentum distribution, and the quasi-particle weight. We find a satisfactory agreement with perturbative results in the weak- and strong-coupling limits. A straightforward extrapolation of the RDA data for $L\leq 14$ lattice results in a continuous Mott-Hubbard transition at $U_{\rm c}\approx W$. We discuss the significance of a possible signature of a coexistence region between insulating and metallic ground states in the RDA that would correspond to the scenario of a discontinuous Mott-Hubbard transition as found in numerical investigations of the Dynamical Mean-Field Theory for the Hubbard model.
dc.description10 pages, 11 figures
dc.identifierhttps://arxiv.org/abs/0811.4271
dc.identifierhttp://arxiv.org/abs/0811.4271
dc.identifierEur. Phys. J. B 66, 191-200 (2008)
dc.identifierdoi:10.1140/epjb/e2008-00402-8
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/208153
dc.subjectStrongly Correlated Electrons
dc.titleRandom dispersion approximation for the Hubbard model
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