The Kondo Lattice Model in Infinite Dimensions I. Formalism

TL;DR

This paper introduces a Green-function formalism for the Kondo lattice model compatible with dynamical mean-field theory, utilizing the t-matrix approach and quantum Monte Carlo methods to compute dynamical correlations.

Contribution

It develops a novel Green-function formalism for the Kondo lattice model that simplifies calculations by using Wick's theorem only for conduction electrons and connects to dynamical mean-field theory.

Findings

Formalism enables calculation of dynamical quantities in the Kondo lattice model.

Explicit computational steps demonstrated with continuous-time quantum Monte Carlo.

Provides a framework for analyzing localized moments in strongly correlated systems.

Abstract

A Green-function formalism for the Kondo lattice model is presented, which is designed to be combined with the dynamical mean-field theory. With use of Wick's theorem only for conduction electrons, dynamical quantities are represented in terms of the t-matrix and its two-particle generalizations. By taking the high-frequency limit of the t-matrix with respect to a part of the fermion frequencies, one obtains dynamical correlation functions of localized moments. Explicit examples of calculational steps are provided with use of the continuous-time quantum Monte Carlo method.