Possible analogies between perovskite superconductors and superconductors with heavy fermions

The interaction between electrons and anharmonic phonons in high-Tc superconductors is examined using a model proposed in an earlier study (Vujicic, 1981) for describing electron-phonon interaction in a strongly anharmonic crystal. In the present analysis, the model is supplemented by a term describing ion tunneling from one hole to another with the participation of conduction-band electrons. It is shown that, in high-Tc superconductors, the interaction of electrons with anharmonic phonons is described by a Kondo lattice Hamiltonian.