Phase Structures of Magnetic Impurity Models with Two-Body Hybridization

TL;DR

This paper investigates the phase structures of magnetic impurity models with two-body hybridization, revealing a Fermi-non-Fermi liquid phase transition and analyzing various finite temperature behaviors and fixed point regimes.

Contribution

It introduces the importance of including two-body hybridization in impurity models and provides a graphical analysis of phase structures and transitions.

Findings

Identification of Fermi-non-Fermi liquid phase transition in the models

All possible phases with distinct finite temperature behaviors

Analysis of fixed point behaviors in the mixed valence regime

Abstract

The most general model with a magnetic impurity coupled to hybridizing and screening channels of a conduction band is considered. The partition function of the system is asymptotically equivalent to that of the multi-component kink plasma with a weak external field. The scaling properties of the models for finite $U$ are sketched by using the Anderson-Yuval-Hamann-Cardy poor man's scaling theory. We point out that it is proper to include a two-body hybridization in order to obtain correct renormalization flows. The phase structures are studied graphically for the general model and various reduced models. A Fermi-non-Fermi liquid phase transition is found for all the models. We also show all possible phases with different finite temperature behaviors though they have the same Fermi liquid fixed point at low temperature. We also discuss the fixed point behaviors in the mixed valence state regime.