Multichannel Kondo Screening in a One-Dimensional Correlated Electron System

TL;DR

This paper provides an exact solution for a multichannel one-dimensional electron system with a magnetic impurity, revealing how interactions influence spin and charge fluctuations and the impurity's effective spin.

Contribution

It introduces an exact Bethe Ansatz solution for a multichannel correlated electron model with a magnetic impurity, highlighting the role of interactions in impurity screening.

Findings

Interactions induce mixed valence at the impurity site.

Impurity screening depends on impurity size, not the number of channels.

Effective impurity spin exceeds the original spin S in a magnetic field.

Abstract

We present the exact Bethe Ansatz solution of a multichannel model of one- dimensional correlated electrons coupled antiferromagnetically to a magnetic impurity of arbitrary spin S. The solution reveals that interactions in the bulk make the magnetic impurity drive both spin and charge fluctuations, producing a mixed valence at the impurity site, with an associated effective spin S_eff > S in the presence of a magnetic field. The screening of the impurity spin is controlled by its size independently of the number of channels, in contrast to the multichannel Kondo effect for free electrons.