# Cavity Carving of Atomic Bell States

## TL;DR

This paper demonstrates a method to generate high-fidelity entangled Bell states of two neutral atoms inside an optical cavity using photon reflection and polarization rotation, advancing quantum network capabilities.

## Contribution

It introduces a cavity carving protocol for entangling atoms that works without individual addressing and at any interatomic distance, with high fidelity.

## Key findings

- Achieved 90% fidelity in Bell state generation.
- Implemented two protocols for entanglement creation.
- Demonstrated protocol's robustness over varying atom distances.

## Abstract

We demonstrate entanglement generation of two neutral atoms trapped inside an optical cavity. Entanglement is created from initially separable two-atom states through carving with weak photon pulses reflected from the cavity. A polarization rotation of the photons heralds the entanglement. We show the successful implementation of two different protocols and the generation of all four Bell states with a maximum fidelity of (90+-2)%. The protocol works for any distance between cavity-coupled atoms, and no individual addressing is required. Our result constitutes an important step towards applications in quantum networks, e.g. for entanglement swapping in a quantum repeater.