Holographic mean field theory and Kondo lattice

TL;DR

This paper develops a holographic mean field theory model for the Kondo lattice, capturing strong coupling effects and hybridization phenomena that are challenging for traditional approaches.

Contribution

It introduces a holographic framework that models the Kondo lattice at strong coupling, incorporating spectral hybridization and symmetry breaking effects.

Findings

Reproduces key features of the Kondo lattice spectrum.

Models hybridization of flat and dispersive bands.

Captures the fuzzy spectrum characteristic of strong coupling.

Abstract

We first study a non-relativistic field theory model for the Kondo lattice by introducing the Kondo condensation, whose main effect is the hybridization of the flat band of the localized electron with dispersive one of the itinerant electron. The problem here is that the resulting Kondo condensation arises only in strong coupling where the validity of the mean field theory is questionable. Therefore, we build a holographic mean field theory of the Kondo lattice with strong coupling by identifying the effect of the lattice with the fermion's spectral shape due to the coupling with the order parameter representing the symmetry breaking. For the flat band spectrum we use the mixed quantization, and for the dispersive spectrum we intoduce the second fermion in standard quantization. The coupling of the two fermions with the scalar order representing the Kondo condensation provides the hybrization of the two spectrum, reproducing the main feature of the Kondo lattice together with the fuzzy character of the spectrum of the strongly coupled system.