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

arXiv:2211.15138 · Physical Review A

Efficient Dicke-state distribution in a network of lossy channels

Wojciech Roga, Rikizo Ikuta, Tomoyuki Horikiri, Masahiro Takeoka

Published Jul 12, 2023• 10 citations
arXivHTMLPDF

Abstract

We analyze the generation of entanglement in a multipartite optical network. We generalize the twin-field strategy to the multipartite case and show that our protocol has advantageous rate-loss scalings of distributing $W$ states and Dicke states over the star networks. We provide precise theoretical formulas and quantitative performance analyses. Also, analysis of the same protocol using Gaussian states as resources, which is a typical setup in many experimental tests, is provided. We numerically study the feasibility of the protocol in realistic experimental conditions with imperfect detectors. We observe that the advantage depends on the chosen fidelity and is affected by the dark counts of the detector.

DOI
10.1103/physreva.108.012612

Related papers

How to Share Multipartite Entanglement in a Real-World Linear Network Connecting Two Metropoles

Janka Memmen, Anna Pappa

The development of large-scale quantum communication networks necessitates the efficient distribution of quantum states to enable advanced cryptographic applications and distributed tasks. Multipartite entanglement is a key resource in many of these proposals, yet its generation is experimentally challenging, especially in noisy and lossy networks. While a substantial body of work focuses on the distribution of multi-partite entanglement in star-like topologies, practical implementations often rely on linear network structures constrained by existing infrastructure. In this work, we investigate the generation of high-fidelity multipartite entangled states in a realistic quantum network, leveraging the existing infrastructure of the Q-net-Q project-a real-world long-distance link connecting Berlin and Frankfurt via seven trusted relay nodes. Given that only bipartite entanglement sources are available in our setting and that the network is highly lossy, we explore the role of quantum memories in enhancing multi-partite entanglement distribution and identify key performance requirements. Furthermore, we analyze the feasibility and performance of cryptographic primitives-including (Anonymous) Conference Key Agreement and Quantum Secret Sharing-highlighting the scenarios where the use of multipartite entanglement yields clear advantages.

arXiv:2507.17480•IEEE International Conference on Quantum Computing and Engineering (QCE)•Aug 30, 2025•1 citation

Heralded optical entanglement distribution via lossy quantum channels: a comparative study

Wan Zo, Seungbeom Chin, Yong‐Su Kim

Quantum entanglement serves as a foundational resource for various quantum technologies. In optical systems, entanglement distribution relies on the indistinguishability and spatial overlap of photons. Heralded schemes play a crucial role in ensuring the reliability of entanglement generation by detecting ancillary photons to signal the creation of desired entangled states. However, photon losses in quantum channels remain a significant challenge, limiting the distance and capacity of entanglement distributions. This study suggests three heralded schemes for distributing multipartite Greenberger-Horne-Zeilinger (GHZ) states via lossy quantum channels. These schemes differ both qualitatively in their network architecture (centralized or decentralized) and photon source requirements (Bell states or single-photons), and quantitatively in their success probabilities and heralding efficiency. Through comprehensive analysis incorporating both practical implementation considerations and theoretical performance metrics, we find that each scheme offers distinct advantages depending on the number of parties, channel distance, and security requirements. The decentralized scheme proves particularly advantageous for networks requiring balanced information distribution, while centralized schemes may offer better performance for smaller networks. This analysis provides insights into designing resilient heralded circuits for quantum information processing over lossy channels, considering both architectural constraints and performance requirements.

arXiv:2409.16622•Optics Express•Feb 28, 2025•2 citations

Loss-Resilient Quantum Networking with Dicke Entanglement

Bowen Wang, Hongyu Yang, Jiacheng Sun +5 more

Multipartite entanglement can endow a quantum network with capabilities unavailable classically, yet their evolution under progressively reduced physical and informational access remains largely unexplored. Here we realize the first eight-photon half-excitation Dicke state, with a fidelity of 0.922(11), and use it to implement two distinct network tasks: open-destination teleportation and quantum telecloning. An unknown state can be teleported from one agent to any of seven remote agents with fidelities of 0.926(7)-0.941(6), while seven approximate clones are distributed with a fidelity of 0.713(3), close to the optimal value of 5/7. The protocol remains above the classical limit under imperfect photon detection, transmission loss and missing information from participating agents, and outperforms the corresponding GHZ benchmarks. As fewer agents contribute, the teleportation fidelity falls through a stepwise hierarchy whose two extremes recover open-destination teleportation and optimal telecloning, connecting both tasks within a single operational framework. These results establish Dicke entanglement as a promising architecture for loss-resilient quantum networks, opening a route towards quantum technologies that retain useful functionality under realistic operating conditions.

quant-pharXiv:2609.33094•Sep 29, 2026•0 citations

Entanglement distribution in lossy quantum networks

Leonardo Oleynik, Junaid ur Rehman, Seid Koudia +1 more

Entanglement distribution is essential for unlocking the potential of distributed quantum information processing. We consider an N-partite network where entanglement is distributed via a central source over lossy channels, and network participants cooperate to establish entanglement between any two chosen parties under local operations and classical communication (LOCC). We develop a general mathematical framework to assess the average bipartite entanglement shared in a lossy distribution, and introduce a tractable lower bound by optimizing over a subset of single-parameter LOCC transformations. Our results show that probabilistically extracting Bell pairs from W states is more advantageous than deterministically extracting them from GHZ-like states in lossy networks, with this advantage increasing with network size. We further extend our analysis analytically, proving that W states remain more effective in large-scale networks. These findings offer valuable insights into the practical deployment of near-term networks, and corroborate a trade-off relationship between the success conversion probability of entanglement distribution protocols and their robustness to loss.

arXiv:2503.24347•Scientific Reports•Aug 14, 2025•2 citations

Deterministic distribution of W-class states in quantum networks

Souvik Chatterjee, Prasenjit Deb, Chandan Datta +1 more

Multipartite entangled states possess a number of non-intuitive properties, making them a useful resource for various quantum information-processing tasks. The three-qubit W-state is one such example where every state is robust to single-qubit loss. However, this state is not suitable for deterministic distribution, and deterministic communication protocols. Here, we focus on the distribution of a non-symmetric version of such states, namely $W_{\mathrm{mod}}$ states. These states belong to the W-class, and have one ebit of entanglement across a specific bipartition, enabling deterministic teleportation and superdense coding. In particular, we describe a few protocols through which these multipartite entangled states can be distributed {\it deterministically} in a quantum network by first preparing them locally in a central node and then transmitting individual qubits to the end nodes. We analyse the performance of these protocols based on the fidelity of the final distributed state, considering all types of noises that can act during the distribution. Finally, we compare the performance of the protocols to the case where the distribution is performed without any central node.

quant-pharXiv:2512.24274•Dec 31, 2025•0 citations

Distributed quantum computation with arbitrarily poor photon detection

Yuichiro Matsuzaki, Simon C. Benjamin, Joseph F. Fitzsimons

In a distributed quantum computer, scalability is accomplished by networking together many elementary nodes. Typically the network is optical and internode entanglement involves photon detection. In complex networks the entanglement fidelity may be degraded by the twin problems of photon loss and dark counts. Here we describe an entanglement protocol which can achieve high fidelity even when these issues are arbitrarily severe; indeed the method succeeds with finite probability even if the photon detectors are entirely removed from the network. An experimental demonstration should be possible with existing technologies.

arXiv:1003.2258•Physical Review A•Jul 22, 2010•6 citations
We analyze the generation of entanglement in a multipartite optical network. We generalize the twin-field strategy to the multipartite case and show that our protocol has advantageous rate-loss scalings of distributing WWW states and Dicke states over the star networks. We provide precise theoretical formulas and quantitative performance analyses. Also, analysis of the same protocol using Gaussian states as resources, which is a typical setup in many experimental tests, is provided. We numerically study the feasibility of the protocol in realistic experimental conditions with imperfect detectors. We observe that the advantage depends on the chosen fidelity and is affected by the dark counts of the detector.
The development of large-scale quantum communication networks necessitates the efficient distribution of quantum states to enable advanced cryptographic applications and distributed tasks. Multipartite entanglement is a key resource in many of these proposals, yet its generation is experimentally challenging, especially in noisy and lossy networks. While a substantial body of work focuses on the distribution of multi-partite entanglement in star-like topologies, practical implementations often rely on linear network structures constrained by existing infrastructure. In this work, we investigate the generation of high-fidelity multipartite entangled states in a realistic quantum network, leveraging the existing infrastructure of the Q-net-Q project-a real-world long-distance link connecting Berlin and Frankfurt via seven trusted relay nodes. Given that only bipartite entanglement sources are available in our setting and that the network is highly lossy, we explore the role of quantum memories in enhancing multi-partite entanglement distribution and identify key performance requirements. Furthermore, we analyze the feasibility and performance of cryptographic primitives-including (Anonymous) Conference Key Agreement and Quantum Secret Sharing-highlighting the scenarios where the use of multipartite entanglement yields clear advantages.
Quantum entanglement serves as a foundational resource for various quantum technologies. In optical systems, entanglement distribution relies on the indistinguishability and spatial overlap of photons. Heralded schemes play a crucial role in ensuring the reliability of entanglement generation by detecting ancillary photons to signal the creation of desired entangled states. However, photon losses in quantum channels remain a significant challenge, limiting the distance and capacity of entanglement distributions. This study suggests three heralded schemes for distributing multipartite Greenberger-Horne-Zeilinger (GHZ) states via lossy quantum channels. These schemes differ both qualitatively in their network architecture (centralized or decentralized) and photon source requirements (Bell states or single-photons), and quantitatively in their success probabilities and heralding efficiency. Through comprehensive analysis incorporating both practical implementation considerations and theoretical performance metrics, we find that each scheme offers distinct advantages depending on the number of parties, channel distance, and security requirements. The decentralized scheme proves particularly advantageous for networks requiring balanced information distribution, while centralized schemes may offer better performance for smaller networks. This analysis provides insights into designing resilient heralded circuits for quantum information processing over lossy channels, considering both architectural constraints and performance requirements.
Multipartite entanglement can endow a quantum network with capabilities unavailable classically, yet their evolution under progressively reduced physical and informational access remains largely unexplored. Here we realize the first eight-photon half-excitation Dicke state, with a fidelity of 0.922(11), and use it to implement two distinct network tasks: open-destination teleportation and quantum telecloning. An unknown state can be teleported from one agent to any of seven remote agents with fidelities of 0.926(7)-0.941(6), while seven approximate clones are distributed with a fidelity of 0.713(3), close to the optimal value of 5/7. The protocol remains above the classical limit under imperfect photon detection, transmission loss and missing information from participating agents, and outperforms the corresponding GHZ benchmarks. As fewer agents contribute, the teleportation fidelity falls through a stepwise hierarchy whose two extremes recover open-destination teleportation and optimal telecloning, connecting both tasks within a single operational framework. These results establish Dicke entanglement as a promising architecture for loss-resilient quantum networks, opening a route towards quantum technologies that retain useful functionality under realistic operating conditions.
Entanglement distribution is essential for unlocking the potential of distributed quantum information processing. We consider an N-partite network where entanglement is distributed via a central source over lossy channels, and network participants cooperate to establish entanglement between any two chosen parties under local operations and classical communication (LOCC). We develop a general mathematical framework to assess the average bipartite entanglement shared in a lossy distribution, and introduce a tractable lower bound by optimizing over a subset of single-parameter LOCC transformations. Our results show that probabilistically extracting Bell pairs from W states is more advantageous than deterministically extracting them from GHZ-like states in lossy networks, with this advantage increasing with network size. We further extend our analysis analytically, proving that W states remain more effective in large-scale networks. These findings offer valuable insights into the practical deployment of near-term networks, and corroborate a trade-off relationship between the success conversion probability of entanglement distribution protocols and their robustness to loss.
Multipartite entangled states possess a number of non-intuitive properties, making them a useful resource for various quantum information-processing tasks. The three-qubit W-state is one such example where every state is robust to single-qubit loss. However, this state is not suitable for deterministic distribution, and deterministic communication protocols. Here, we focus on the distribution of a non-symmetric version of such states, namely WmodW_{\mathrm{mod}}Wmod​ states. These states belong to the W-class, and have one ebit of entanglement across a specific bipartition, enabling deterministic teleportation and superdense coding. In particular, we describe a few protocols through which these multipartite entangled states can be distributed {\it deterministically} in a quantum network by first preparing them locally in a central node and then transmitting individual qubits to the end nodes. We analyse the performance of these protocols based on the fidelity of the final distributed state, considering all types of noises that can act during the distribution. Finally, we compare the performance of the protocols to the case where the distribution is performed without any central node.
In a distributed quantum computer, scalability is accomplished by networking together many elementary nodes. Typically the network is optical and internode entanglement involves photon detection. In complex networks the entanglement fidelity may be degraded by the twin problems of photon loss and dark counts. Here we describe an entanglement protocol which can achieve high fidelity even when these issues are arbitrarily severe; indeed the method succeeds with finite probability even if the photon detectors are entirely removed from the network. An experimental demonstration should be possible with existing technologies.