Kondo temperature equation for the Fermi liquid and the non-Fermi liquid regime for a two-channel anderson model

Abstract

Multichannel Kondo resonance causes non-Fermi liquid behavior in many systems, as nanostructured metallic quantum dots and metallic alloys. The Kondo effect occurs at low temperatures and its indicating parameter is the Kondo temperature TK. This parameter can be used to renormalize thermodynamic and transport properties. The Kondo temperature is an important quantity to analyze the antiferromagnetic interaction between a localized spin and itinerant ones in a fermionic bath. There are many different definitions of the Kondo temperature. One of them is that it universalizes magnetic impurity susceptibility. This version was created for the one-channel Anderson model, but it is also valid in two-channel Anderson models, where a single magnetic impurity interacts with the conduction band electrons by two different channels. If the two coupling parameters are different, the model exhibits the well known Fermi liquid regime. When the coupling parameters are equal, the model displays the non-Fermi liquid regime. Each one shows different universal magnetic susceptibility behavior with appropriate TK value. In this article, Numerical Renormalization Group method is applied to study the Kondo temperature systematically. Different values of the coupling parameters in a two-channel Anderson model are examined. Finally, a single analytic expression for the Kondo temperature, valid in the Fermi and non-Fermi liquid regime, is presented.