SU(3) Anderson impurity model: A numerical renormalization group approach exploiting non-Abelian symmetries

TL;DR

This paper extends the density-matrix NRG method to incorporate non-Abelian symmetries like SU(3), enabling detailed analysis of the Anderson impurity model's spectral functions and conductance with a focus on its Fermi liquid properties.

Contribution

It introduces a scheme combining DM-NRG with non-Abelian symmetries, specifically SU(3), for the first time applied to the Anderson model.

Findings

Revealed a rich Fermi liquid structure in the SU(3) Anderson model.

Analyzed finite size spectrum and spectral functions.

Computed temperature-dependent conductance.

Abstract

We show how the density-matrix numerical renormalization group (DM-NRG) method can be used in combination with non-Abelian symmetries such as SU(N), where the decomposition of the direct product of two irreducible representations requires the use of a so-called outer multiplicity label. We apply this scheme to the SU(3) symmetrical Anderson model, for which we analyze the finite size spectrum, determine local fermionic, spin, superconducting, and trion spectral functions, and also compute the temperature dependence of the conductance. Our calculations reveal a rich Fermi liquid structure.