Exact conformal-field-theory results on the multichannel Kondo effect: Single-fermion Green’s function, self-energy, and resistivity

Abstract

A conformal-field-theory approach has recently been developed for quantum-impurity problems including the ‘‘overscreened’’ multichannel Kondo model. We present the details of our calculation of the single-fermion Green’s function. The universal zero-temperature resistivity and leading temperature-dependent term are derived. Effects of particle-hole symmetry breaking are included. We also give our perturbative proof of the ‘‘g theorem’’ governing the change in residual entropy under a renormalization-group flow between two boundary fixed points.