Phonon-Mediated Attractive Interaction between Adjacent f Electrons in Heavy-Electron Superconductors

抄録

An electron-phonon interaction in Kondo lattices is theoretically investigated. It is significantly screened by the Kondo effect, while the Thomas-Fermi type screening is weak in spite of a large specific heat coefficient. These features are owing to the reduction of the charge susceptibility by the Kondo effect. It is argued that the attractive interaction between adjacent f electrons due to one-phonon exchange can overcome the on-site repulsive interaction due to Coulomb correlation for reasonable values of physical parameters, when ligands are composed of many ions, i.e., clusters, and modes besides the center of mass contribute to one-phonon exchange.