Quantum entanglement in a pure state of strongly correlated quantum impurity systems

TL;DR

This paper investigates quantum entanglement in strongly correlated impurity systems, using quantum informational measures to analyze states like the Kondo effect and duality between itineracy and localization.

Contribution

It introduces a method to quantify quantum entanglement in impurity systems using entanglement entropy, mutual information, and relative entropy, applied to models like the Anderson model.

Findings

Entanglement measures reveal correlations in impurity states.

The method helps understand the relationship between impurity states and quantum informational quantities.

Results suggest the approach is promising for studying quantum entanglement in impurity systems.

Abstract

We consider quantum entanglement in strongly correlated quantum impurity systems for states manifesting interesting properties such as multi-level Kondo effect and dual nature between itineracy and localization etc.. For this purpose, we set up a system consisting of one or two quantum impurities arbitrarily selected from the system as a subsystem, and investigate quantum entanglement with its environmental system. We reduce the pure state of interest as described above to the subsystem, and formulate quantum informative quantities such as entanglement entropy, mutual information and relative entropy. We apply them to quantum impurity systems consisting of several sites and the single impurity Anderson model to study the relationship between their states and the behaviors of quantum informative quantities. The obtained results suggest that the method proposed here is promising for elucidating the quantum entanglement of pure states in various quantum impurity systems.