Two Impurity Anderson problem: Perturbative Kondo-Doublet interaction

TL;DR

This paper uses perturbation theory to analyze the Kondo-Doublet interaction in the two impurity Anderson model, showing its relation to the Kondo screening cloud and dominance in quantum dot systems.

Contribution

It demonstrates the derivation of the Kondo-Doublet interaction via perturbation theory and clarifies its physical origin and parameter dependence.

Findings

Kondo-Doublet interaction is a direct consequence of the Kondo screening cloud.

In quantum dot systems, the ferromagnetic Kondo-Doublet interaction dominates over RKKY.

The perturbative approach confirms previous results on the Kondo-Doublet interaction.

Abstract

We reobtain the Kondo-Doublet interaction by means of the Brillouin-Wigner Perturbation theory. By applying the same method to the single impurity case we show that the Kondo-Doublet interaction is a direct consequence of the Kondo screening cloud. We fully confirm our previous results on this novel interaction. In particular, we found that for values of the system parameters typical of semiconductor Quantum Dots heterostructures, the ferromagnetic Kondo-Doublet interaction dominates over the RKKY one.