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Correlated hopping of electrons: Effect on the Brinkman-Rice transition and the stability of metallic ferromagnetism

M. Kollar·D. Vollhardt
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Abstract

We study the Hubbard model with bond-charge interaction (`correlated hopping') in terms of the Gutzwiller wave function. We show how to express the Gutzwiller expectation value of the bond-charge interaction in terms of the correlated momentum-space occupation. This relation is valid in all spatial dimensions. We find that in infinite dimensions, where the Gutzwiller approximation becomes exact, the bond-charge interaction lowers the critical Hubbard interaction for the Brinkman-Rice metal-insulator transition. The bond-charge interaction also favors ferromagnetic transitions, especially if the density of states is not symmetric and has a large spectral weight below the Fermi energy.

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M. Kollar, D. Vollhardt. 2001-01-16. Correlated hopping of electrons: Effect on the Brinkman-Rice transition and the stability of metallic ferromagnetism. https://doi.org/10.1103/physrevb.63.045107

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