engleski

Algebraic extraction of one-particle fields induced by repulsion on copper sites in the Emery model

A model of free fermions is described, which embodies the strong local correlations on copper sites in the CuO/sub 2/ planes. One-particle fields induced by the correlations are extracted algebraically and found to renormalize the copper-oxygen hopping and change the band-widths of the effective one-particle Hamiltonian. The strength of these fields is adjusted through a single variational parameter, dependent on the band filling. It is found that additional hoppings appear among oxygen sites, even if only the copper-oxygen overlap was originally present.

strong correlations; high-Tc superconductors

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