Entanglement in helium

TL;DR

This paper calculates the electron-electron entanglement in helium's low-energy states using a variational method, revealing that entanglement decreases as energy increases.

Contribution

It introduces an accurate variational approach to quantify electron entanglement in helium's eigenstates, highlighting its energy dependence.

Findings

Entanglement decreases with increasing energy in helium states.

Accurate computation of single-electron von Neumann entropy.

Provides insights into electron correlation in helium.

Abstract

Using a configuration-interaction variational method, we accurately compute the reduced, single-electron von Neumann entropy for several low-energy, singlet and triplet eigenstates of helium atom. We estimate the amount of electron-electron orbital entanglement for such eigenstates and show that it decays with energy.