Ultrafast preparation and strong-field ionization of an atomic Bell-like state

TL;DR

This paper demonstrates a femtosecond-scale method to create and detect entangled atomic states from diatomic molecules, specifically entangling two oxygen atoms in their valence electron magnetic quantum numbers using strong-field ionization.

Contribution

It introduces a novel scheme for preparing Bell-like entangled states of atoms derived from molecules and employs non-adiabatic tunnel ionization to probe their entanglement properties.

Findings

Successful preparation of entangled oxygen atom pairs.

Agreement between experimental results and entanglement predictions.

Femtosecond-scale entanglement generation and detection.

Abstract

Molecules are many body systems with a substantial amount of entanglement between their electrons. Is there a way to break the molecular bond of a diatomic molecule and obtain two atoms in their ground state which are still entangled and form a Bell-like state? We present a scheme that allows for the preparation of such entangled atomic states from single oxygen molecules on femtosecond time scales. The two neutral oxygen atoms are entangled in the magnetic quantum number of their valence electrons. In a time-delayed probe step, we employ non-adiabatic tunnel ionization, which is a magnetic quantum number-sensitive mechanism. We then investigate correlations by comparing single and double ionization probabilities of the Bell-like state. The experimental results agree with the predictions for an entangled state.