A MODIFIED BCS THEORY OF HEAVY-FERMION SUPERCONDUCTIVITY

In this paper we derive an expression for the superconducting transition temperature of a uranium-based heavy-fermion system within a modified weak-coupling theory of superconductivity. It is found that the energy dependence of the enhanced density of states for the heavy-fermion system clearly manifests itself in the theory, and the Kondo energy naturally takes the role of cut-off, as long as the effective cut-off energy is large in comparison. The numerical analysis confirms this result and shows that the superconducting transition temperature is indeed independent of the effective cut-off energy employed within the approach.