Correlated hopping of electrons: Effect on the Brinkman-Rice transition and the stability of metallic ferromagnetism - art. no. 045107

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