Renormalized perturbation theory and scaling for an impurity Anderson model

TL;DR

This paper introduces a generalized renormalized perturbation approach to accurately compute the magnetization in the single impurity Anderson model across various interaction strengths, validated against established numerical methods.

Contribution

It develops a flow equation-based scaling method that effectively bridges weak and strong correlation regimes for the Anderson model, providing accurate results with simple approximations.

Findings

Accurate magnetization calculations across all magnetic fields.

Validation against numerical renormalization group and Bethe ansatz results.

Effective scaling from weak to strong correlations.

Abstract

We demonstrate the effectiveness of a generalized renormalized perturbational approach to calculate the induced magnetization for the single impurity Anderson model with a strong on-site interaction, using flow equations for renormalized parameters to scale from a weak correlation to a strong correlation regime. We show that, using simple approximation schemes in different parameter regimes, remarkably accurate results can be obtained for all magnetic field values by comparing the results with those from direct numerical renormalization group and Bethe ansatz calculations.