Metal-antiferromagnetic insulator transition in the charge-transfer model.

Abstract

We apply the mean-field slave-boson treatment proposed by Arrigoni and Strinati to the charge-transfer model which describes holes in the ${\mathrm{CuO}}_{2}$ planes of high-temperature superconductors and compare the results with the conventional Gutzwiller approximation. In both cases the increasing Coulomb interaction gives a transition from a correlated metal to a charge-transfer antiferromagnetic insulator, which replaces the Brinkman-Rice transition. The interoxygen hopping stabilizes the metallic phase, but does not change the qualitative phase diagram.