On The Multichannel Kondo Model"

TL;DR

This paper provides a detailed analysis of the multichannel Kondo model at large channel numbers, revealing critical fixed points, universal degeneracy, and localized screening effects through perturbative methods.

Contribution

It introduces a perturbative approach in 1/k to study the low energy fixed point of the multichannel Kondo model, clarifying its criticality and universal properties.

Findings

Identification of the critical fixed point.

Demonstration of universal non-integer degeneracy.

Localization of the screening cloud within one lattice spacing.

Abstract

A detailed and comprehensive study of the one-impurity multichannel Kondo model is presented. In the limit of a large number of conduction electron channels $k \gg 1$, the low energy fixed point is accessible to a renormalization group improved perturbative expansion in $1/k$. This straightforward approach enables us to examine the scaling, thermodynamics and dynamical response functions in great detail and make clear the following features: i) the criticality of the fixed point; ii) the universal non-integer degeneracy; iii) that the compensating spin cloud has the spatial extent of the order of one lattice spacing.