Entanglement in helium atom confined in an impenetrable cavity

TL;DR

This paper investigates how the entanglement properties of a helium atom change when confined within an impenetrable spherical cavity, revealing detailed dependencies and identifying signatures of strong confinement through entropic measures.

Contribution

It provides highly accurate numerical results for entanglement entropies of confined helium and analyzes their behavior across different confinement regimes, including the first detailed report of such data.

Findings

Entanglement entropies depend on cavity radius with identifiable inflection points.

Transition to strong confinement is marked by changes in entanglement measures.

First detailed numerical results for von Neumann and linear entropy of confined helium.

Abstract

We explore ground-state entanglement properties of helium atom confined at the center of an impenetrable spherical cavity of varying radius by using explicitly correlated Hylleraas-type basis set. Results for the dependencies of the von Neumann and linear entanglement entropic measures on the cavity radius are discussed in details. Some highly accurate numerical results for the von Neumann and linear entropy are reported for the first time. It is found that the transition to the strong confinement regime is manifested by the entropies as an appearance of the inflection points on their variations.