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  • Featured in Physics
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Source of Heralded Atom-Photon Entanglement for Quantum Networking

Gianvito Chiarella1, Tobias Frank1, Leart Zuka1, Pau Farrera1,2,*, and Gerhard Rempe1

  • *Contact author: pau.farrera@mpq.mpg.de
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Phys. Rev. Lett. 135, 240802 – Published 10 December, 2025

DOI: https://doi.org/10.1103/5zk9-3rpv

Abstract

Communication in quantum networks suffers notoriously from photon loss. Resulting errors can be mitigated with a suitable measurement herald at the receiving node. However, waiting for a herald and communicating the measurement result back to the sender in a repeat-until-success strategy makes the protocol slow and prone to errors from false heralds such as detector dark counts. Here, we implement an entanglement herald at the sending node by employing a cascaded two-photon emission of a single atom into two optical fiber cavities: the polarization of one photon is entangled with the spin of the atom, and the second photon heralds entanglement generation. We show that heralding improves the atom-photon entanglement in-fiber efficiency and fidelity to 68(3)% and 87(2)%, respectively. We highlight the potential of our source for noise-limited long-distance quantum communication by extending the range for constant fidelity or, alternatively, increasing the fidelity for a given distance.

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synopsis

Step Toward Practical Quantum Networks

Published 10 December, 2025

A new strategy boosts both the efficiency and reliability of quantum communication networks.

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Article Text

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Outline

Information

Phys. Rev. Lett. 135, 240802– Published 10 December, 2025
  • Received 17 June 2025
  • Revised 11 September 2025
  • Accepted 22 October 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

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