Eur. Phys. J. D (2015) 69: 250
https://doi.org/10.1140/epjd/e2015-60453-4

Regular Article

Entanglement in helium atom confined in an impenetrable cavity

¹ Institute of Physics, Jan Kochanowski University, ul. Świętokrzyska 15, 25-406 Kielce, Poland
² Indian Association for the Cultivation of Science, Jadavpur, 700032 Kolkata, India

^a e-mail: jsaha84@gmail.com

Received: 3 August 2015
Received in final form: 13 September 2015
Published online: 10 November 2015

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.