Non-Fermi liquid behavior in an extended Anderson model

TL;DR

This paper investigates a generalized Anderson model with screening channels, revealing non-Fermi liquid behavior through correlation functions, and discusses its implications for heavy fermion systems.

Contribution

It introduces an extended Anderson model with screening channels and analyzes its non-Fermi liquid properties using the Anderson-Yuval approach, a novel application for this context.

Findings

Correlation functions exhibit non-Fermi liquid exponents.

Exponent depends on scattering potential strength.

Relevance to heavy fermion experiments is discussed.

Abstract

An extended Anderson model, including screening channels (non-hybridizing, but interacting with the local orbit), is studied within the Anderson-Yuval approach, originally devised for the single-channel Kondo problem. By comparing the perturbation expansions of this model and a generalized resonant level model, the spin-spin correlation functions are calculated which show non-Fermi liquid exponent depending on the strength of the scattering potential. The relevance of this result to experiments in some heavy fermion systems is briefly discussed.