Simplified Thermodynamics for Quantum Impurity Models

TL;DR

This paper introduces a simplified, transparent method to calculate thermodynamic properties of integrable quantum impurity models, demonstrated on the Kondo and resonant level models, valid across all temperatures and couplings.

Contribution

The paper presents a new simplified integral equation approach for thermodynamics of quantum impurity models, improving understanding and computational efficiency.

Findings

Derived a single integral equation for free energy

Validated method on Kondo and resonant level models

Applicable at all temperatures and coupling strengths

Abstract

Quantum impurity models play an important role in many areas of physics from condensed matter to AMO and quantum information. They are important models for many physical systems but also provide key insights to understanding much more complicated scenarios. In this paper we introduce a simplified method to describe the thermodynamic properties of integrable quantum impurity models. We show this method explicitly using the anisotropic Kondo and the interacting resonant level models. We derive a simplified expression for the free energy of both models in terms of a single physically transparent integral equation which is valid at all temperatures and values of the coupling constants.