Acoustic plasmons in heavy-fermion superconductors

A possible low-lying excitation mode, the acoustic plasmon, in the heavy-fermion superconductors with s and f electrons has been obtained. It was shown that under certain conditions the acoustic plasmon exchange between electrons can lead to the formation of not only s-s electron pairs, but also s-f electron hybrid pairs. The RPA approximation is used to calculate the dielectric function, to derive the expression for the superconducting transition temperature and to discuss the effect of hybrid pairs. In addition, the possibility of existence of the acoustic plasmons in the heavy-fermion superconductors was examined based on the analysis of the anomalies in the specific heat