Simple embedding scheme for the spectral properties of the Single-Impurity Anderson Model

TL;DR

This paper presents a simple, cost-effective spectral analysis method for the single-impurity Anderson model, combining DMET and NRG-inspired broadening, achieving results comparable to advanced numerical techniques.

Contribution

The authors introduce a novel, straightforward approach that effectively captures spectral features of the Anderson model, with potential applicability to more complex impurity systems.

Findings

Spectral functions agree well with advanced methods across various U values.

The approach is numerically inexpensive and easily transferable.

Results are consistent at zero temperature.

Abstract

In this work we outline a simple and numerically inexpensive approach to describe the spectral features of the single-impurity Anderson model. The method combines aspects of the density matrix embedding theory (DMET) approach with a spectral broadening approach inspired by those used in numerical renormalization group (NRG) methods. At zero temperature for a wide range of U , the spectral function produced by this approach is found to be in good agreement with general expectations as well as more advanced and complex numerical methods such as DMRG-based schemes. The theory developed here is simply transferable to more complex impurity problems.