SUPERCONDUCTIVITY IN ANDERSON LATTICE MODEL

We study the superconducting instabilities generated by the inclusion in the Anderson lattice model of a density-density attractive potentia l between correlated electrons on nearest-neighbouring sites. Using a description of the normal phase based on a perturbative expansion arou nd the atomic limit, we treat the attractive potential in the broken-s ymmetry Hartree-Fock scheme and analyze which of the possible symmetri es of the superconducting order parameter leads to the highest possibl e transition temperature in the case of a two-dimensional square latti ce. For values of the on-site f-repulsion large compared to the hoppin g amplitude, a suppression of any possible superconducting phase occur s, regardless of the symmetry of the order parameter.