Quasiparticle mass enhancement as a measure of entanglement in the Kondo problem

TL;DR

This paper demonstrates that in the Anderson impurity model, the quantum entanglement between opposite spin electrons correlates monotonically with quasiparticle mass enhancement, linking entanglement to measurable many-body effects.

Contribution

It establishes a universal relationship between spin entanglement and quasiparticle mass enhancement in the Anderson model, combining analytical and numerical methods.

Findings

Entanglement is a monotonic function of mass enhancement Z.

Mass enhancement can quantify spin entanglement in many-body systems.

The relationship is universal across the model's parameters.

Abstract

We analyze the quantum entanglement between opposite spin projection electrons in the ground state of the Anderson impurity model. In this model, a single level impurity with intralevel repulsion U is tunnel coupled to a free electron gas. The Anderson model presents a strongly correlated many body ground state with mass enhanced quasiparticle excitations. We find, using both analytical and numerical tools, that the quantum entanglement between opposite spin projection electrons is a monotonic universal function of the quasiparticle mass enhancement Z. The mass enhancement, which is used to quantify the correlations in quantum many body systems, could therefore be used to quantify spin entanglement.