Simple description of the anisotropic two-channel Kondo problem

TL;DR

This paper presents a simplified theoretical approach to the anisotropic two-channel Kondo model, revealing non-Fermi liquid behavior through a compactified Hamiltonian and impurity S-matrix analysis.

Contribution

It adapts strong-coupling methods to describe the anisotropic two-channel Kondo model, emphasizing spin-charge decoupling and fixed-point structure.

Findings

The fixed-point Hamiltonian indicates non-Fermi liquid behavior.

The impurity S-matrix structure is incompatible with Fermi liquid theory.

The method provides a simplified yet accurate description of the model.

Abstract

We adapt strong-coupling methods first used in the one-channel Kondo model to develop a simple description of the spin-$1\over 2$ two-channel Kondo model with channel anisotropy. Our method exploits spin-charge decoupling to develop a compactified Hamiltonian that describes the spin excitations. The structure of the fixed-point Hamiltonian and quasiparticle impurity S-matrix are incompatible with a Fermi liquid description.