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Strategies for entanglement distribution in optical fiber networks

Hannah McAleese1,*, Anuj Agrawal2, Vivek Vasan2, Conall J. Campbell1, Adam G. Hawkins1, Daniel C. Kilper2, Mauro Paternostro3,1, and Marco Ruffini2

  • *Contact author: hmcaleese02@qub.ac.uk
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Phys. Rev. Research 7, 043105 – Published 27 October, 2025

DOI: https://doi.org/10.1103/84qz-1jz2

Abstract

Distributing entanglement over long distances remains a challenge due to its fragility when exposed to environmental effects. In this work, we compare various entanglement distribution protocols in a realistic noisy fiber network. We focus specifically on two schemes that only require the sending of a nonentangled carrier photon to remote nodes of the network. These protocols rely on optical cnot/cphase gates, and we vary the probability with which they can be successfully performed. Encoding our entangled states in photon polarization, we analyze the effect of depolarizing noise on the photonic states as the carrier passes through the fibers. Building a robust model of photon loss and calculating the distillable entanglement of the noisy states, we find the entanglement distribution rate. We discover that methods involving a separable carrier can reach a higher rate than the standard entanglement distribution protocol, provided that the success probability of the optical cnot/cphase gates is sufficiently high.

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Phys. Rev. Research 7, 043105– Published 27 October, 2025
  • Received 29 November 2024
  • Accepted 25 September 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.

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