Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum 2.0 Conference and Exhibition

Towards Entanglement Swapping over 250 km of Deployed Fiber

Chase Wallace, Tsering Lodhen, Leonardo Castillo-Veneros, Anthony Del Valle, Dounan Du, Samuel Woronick, Dimitrios Katramatos, Julián Martínez-Rincón, Sonali Gera, Eden V. Figueroa

Published Jan 1, 2025• 0 citations
Publisher

Abstract

We report our progress towards performing entanglement swapping using deployed fiber in a five-node 259 km network testbed connecting Long Island and New York City.
DOI
10.1364/quantum.2025.qw4a.6

Related papers

Towards a Long Distance Memory Assisted Quantum Repeater

Chase Wallace, Tsering Lodhen, Leonardo Castillo-Veneros +7 more

We report our progress towards performing memory-assisted entanglement swapping using deployed fiber in a five-node 259 km network testbed. Our quantum repeater testbed is envisioned to push beyond the PLOB boundary of repeaterless networks.

Quantum 2.0 Conference and Exhibition•Jan 1, 2024•1 citation

Towards entanglement swapping over 30 km in a three-node metropolitan quantum network in New York City

Niccolò Bigagli, Alexander N. Craddock, Tyler Cowan +2 more

We report on our work towards entanglement swapping in a three-node quantum network between lower Manhattan and Brooklyn using bichromatic rubidium-based entanglement sources.

Quantum 2.0 Conference and Exhibition•Jan 1, 2025•0 citations

Automated distribution of polarization entangled photons using deployed New York City fibers and beyond

Alexander N. Craddock, Anne Lazenby, Gabriel Bello Portmann +6 more

We showcase the distribution of entanglement in various use cases in deployed fiber testbeds. Our work demonstrates the practical high rate, high fidelity entanglement distribution is presently achievable.

Quantum 2.0 Conference and Exhibition•Jan 1, 2025•0 citations

High-rate Scalable Entanglement Swapping Between Remote Entanglement Sources on Deployed New York City Fibers

Alexander N. Craddock, Tyler Cowan, Niccolò Bigagli +11 more

Entanglement swapping between photon pairs generated at physically separated nodes over telecommunication fiber infrastructure is an essential step towards the quantum internet, enabling applications such as quantum repeaters, blind quantum computing, distributed quantum computing, and distributed quantum sensing. However, successful networked entanglement swapping relies on generating indistinguishable pairs of photons and preserving them over deployed fibers. This has limited most previous demonstrations to laboratory settings or relied on sophisticated methods to maintain the necessary indistinguishability. Here, we demonstrate a scalable entanglement swapping experiment using naturally indistinguishable entanglement sources based on warm atomic vapor cells. Without sharing lasers or optical frequency references between nodes, nor the need for pulsing the sources, we achieve a swapping rate of nearly 500 pairs/s while maintaining the CHSH parameter above 2. Additionally, we demonstrate the scalability of our method by maintaining the quality of the entanglement swapping on 17.6-km of deployed fibers in NYC, relying on commercially available SPADs at the spoke nodes, SNSPDs at the hub and standard time-synchronization techniques. Our work paves the way for the practical deployment of large-scale hub-and-spoke quantum networks within cities and data centers.

quant-pharXiv:2602.15653•PRX Quantum•Feb 18, 2026•2 citations

Entanglement swapping across a five-node relay in a multiplexed quantum-classical network

Andrew R. Cameron, Jordan M. Thomas, Alexandru Macridin +9 more

Quantum networks are resources for scaling quantum computers and distributed sensing technologies while offering post-quantum security benefits. Teleporting non-classical resources like entanglement, via so called entanglement swapping, is essential for networks in particular overcoming rate-loss limits via quantum repeaters. Deploying these systems on real infrastructure will likely require multiplexing photonic qubits into fibers carrying 'classical' light encoding standard Internet communications and control plane signals for multi-node quantum protocols. Here, we report the first demonstration of entanglement swapping and conventional communications operating over the same fibers. Entanglement is swapped across a five-node quantum relay topology connected by four long-distance fibers, each populated with classical data signals. Time-bin entangled photons in the C-band are multiplexed alongside C-band classical signals using dense-wavelength division multiplexing, introducing noise photons generated by high-power classical light. We experimentally and theoretically characterize the trade-off between quantum fidelity and Raman noise photons. Entanglement swapping is demonstrated over a maximum fiber length of 40 km (four 10-km fibers) while simultaneously transmitting 10-Gbps classical data through all fibers. These results represent a significant advancement in the demonstrated complexity of coexisting quantum and classical networks and provide a roadmap for achieving the widespread deployment of advanced quantum technologies.

quant-pharXiv:2609.18899•Sep 17, 2026•0 citations

Witnessing effective entanglement over 2km of optical fiber

Wittmann, Fürst, Wiechers +4 more

Conference on Lasers and Electro-Optics•Jan 1, 2010•0 citations
Entanglement swapping between photon pairs generated at physically separated nodes over telecommunication fiber infrastructure is an essential step towards the quantum internet, enabling applications such as quantum repeaters, blind quantum computing, distributed quantum computing, and distributed quantum sensing. However, successful networked entanglement swapping relies on generating indistinguishable pairs of photons and preserving them over deployed fibers. This has limited most previous demonstrations to laboratory settings or relied on sophisticated methods to maintain the necessary indistinguishability. Here, we demonstrate a scalable entanglement swapping experiment using naturally indistinguishable entanglement sources based on warm atomic vapor cells. Without sharing lasers or optical frequency references between nodes, nor the need for pulsing the sources, we achieve a swapping rate of nearly 500 pairs/s while maintaining the CHSH parameter above 2. Additionally, we demonstrate the scalability of our method by maintaining the quality of the entanglement swapping on 17.6-km of deployed fibers in NYC, relying on commercially available SPADs at the spoke nodes, SNSPDs at the hub and standard time-synchronization techniques. Our work paves the way for the practical deployment of large-scale hub-and-spoke quantum networks within cities and data centers.
Quantum networks are resources for scaling quantum computers and distributed sensing technologies while offering post-quantum security benefits. Teleporting non-classical resources like entanglement, via so called entanglement swapping, is essential for networks in particular overcoming rate-loss limits via quantum repeaters. Deploying these systems on real infrastructure will likely require multiplexing photonic qubits into fibers carrying 'classical' light encoding standard Internet communications and control plane signals for multi-node quantum protocols. Here, we report the first demonstration of entanglement swapping and conventional communications operating over the same fibers. Entanglement is swapped across a five-node quantum relay topology connected by four long-distance fibers, each populated with classical data signals. Time-bin entangled photons in the C-band are multiplexed alongside C-band classical signals using dense-wavelength division multiplexing, introducing noise photons generated by high-power classical light. We experimentally and theoretically characterize the trade-off between quantum fidelity and Raman noise photons. Entanglement swapping is demonstrated over a maximum fiber length of 40 km (four 10-km fibers) while simultaneously transmitting 10-Gbps classical data through all fibers. These results represent a significant advancement in the demonstrated complexity of coexisting quantum and classical networks and provide a roadmap for achieving the widespread deployment of advanced quantum technologies.