Two Channel Multi impurity Kondo model

TL;DR

This paper investigates the effects of inter-impurity interactions in two-channel Kondo systems, revealing a new quantum critical point with unique scaling properties relevant to various strongly correlated materials.

Contribution

It demonstrates that RKKY interactions are relevant perturbations in multi-impurity two-channel Kondo models, leading to a novel quantum critical point with specific anomalous dimensions.

Findings

Identification of a new quantum critical point for N>3 impurities.

Scaling of the Sommerfeld coefficient as γ ∼ T^(-3/(N+1)).

Relevance to impurity systems in Majorana metals and heavy fermion materials.

Abstract

We show that the Ruderman-Kittel-Kasua-Yoisida interaction between overscreened spins in two channel Kondo impurity systems is a relevant perturbation when the number of impurities N is greater than 3 driving the system to a new quantum critical point with anomalous dimensions $\frac{1}{ (N+1)} $ for the spin operator and the Sommerfeld coefficient of the specific heat scales as $\gamma \sim T^{- \frac{3}{N+1}}$. The critical point universal properties are relevant to many strong correlation problems, such as impurity placed in a Majorana metal and the multichannel Kondo lattice model of heavy fermion materials. We discuss relevance of our results for cluster DMFT studies of quantum criticality.