Mechanism for heavy-fermion superconductivity

Abstract

A method has been developed to obtain an effective interaction between heavy quasiparticles that exist in heavy-fermion systems by combining the effects of the Coulomb interactions and the electron-phonon interactions that act among various constituents (heavy quasiparticles, light quasiparticles, phonons, non-f atoms) of the system. The effective interaction is expressed in terms of microscopic parameters of the heavy-fermion systems. The role of the new effective interaction in determining superconducting order in heavy-fermion systems at low temperatures has been clarified. It is found that an appropriate strength of the new interaction leads to p-wave superconductivity. Values of the superconducting transition temperature calculated by using the new interaction for different heavy-fermion systems are in good agreement with the experimental values of the superconducting transition temperature for reasonable magnitudes of quasiparticle bandwidths. General features of the new interaction have been discussed.