Quasiparticle Mass Enhancement as a Measure of Entanglement in the Kondo Problem

GARCIÁ, D.J.; PARI, NAYRA A. ÁLVAREZ; CORNAGLIA, PABLO S.

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Año: 2020 vol. 125

0031-9007

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 in the Kondo regime. This indicates that the interaction induced mass enhancement, which is generally used to quantify correlations in quantum many body systems, could be used as a measure of entanglement in the Kondo problem.