Cooper Pairing between Strongly and Weakly Correlated Electrons

抄録

A possible mechanism for superconductivity in heavy-fermion systems is presented on the basis of the infinite-U periodic Anderson model. It is shown that the interaction between a strongly correlated electron (f-electron) and a weakly correlated electron (conduction electron) resulting from a virtual exchange of density fluctuation of the strongly correlated electrons is attractive for singlet pairing. The expressions of the free energy and the self-consistent equations for the gap parameter and T_C are obtained in the Hartree-Fock approximation. Similar considerations can also be applied to high-T_C superconductors in which 3d-electrons of Cu²⁺ and p-electrons of O²⁻ play roles of strongly correlated and weakly correlated electrons, respectively.