Heralded W state preparation using laser-designed super-atoms

TL;DR

This paper presents a heralded scheme for preparing maximally entangled W states in atomic ensembles using Rydberg blockade, with fidelity independent of atom number, enabling reliable entanglement in fluctuating atom clouds.

Contribution

It introduces a novel protocol leveraging ion detection as a herald for successful W state preparation, independent of atom number fluctuations.

Findings

Fidelity of W state preparation is independent of atom number.

Ion detection reliably indicates successful entanglement.

Protocol is robust against atom number fluctuations.

Abstract

We propose a scheme for preparing an ensemble of atoms in a maximally entangled W state by exploiting the Rydberg blockade effect. The success of our protocol is indicated by the detection of an ion, which thus serves as a herald for successful entangled state preparation. The fidelity of the preparation scheme is independent of the number of atoms in the ensemble. Therefore, a small cloud of atoms in a dipole trap randomly loaded from a background gas can be reliably prepared in a maximally entangled state despite of atom number fluctuations.