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:2603.25920 · Journal of Optical Communications and Networking

Impact of Topology on Multipartite Entanglement Distribution Protocols in Quantum Networks

Jazz E. Z. Ooi, Evan Sutcliffe, Alejandra Beghelli

quant-phSubmitted Mar 26, 2026• Announced Mar 30, 2026• 0 citations
v1 · Mar 26, 2026v2 · Jul 20, 2026
arXivHTMLPDF

Abstract

Quantum networks will rely on entanglement distribution to enable multi-user applications such as distributed quantum computing and cryptography. While multipartite entanglement distribution routing protocols have been extensively studied on idealised grid topologies, less is understood about how real network structure shapes their performance and resource requirements. We present a systematic study of four routing protocols for multipartite entanglement distribution, each characterised by the number of paths (single-path and multi-path) and routing strategy (star-based and tree-based), over 81 real network topologies. We identified four distinct topology-dependent performance regimes, where: (i) all protocols perform poorly, (ii) tree-based protocols dominate, (iii) multi-path protocols dominate, or (iv) all protocols perform well. By correlating clusters with graph metrics, we also provide structural explanations for the varied performance of specific protocols. Additionally, motivated by the anticipated high cost of repeaters, we investigated the impact of repeater trimming on the performance of multi-path protocols. Topology strongly governs how far repeater nodes can be removed from the network while maintaining a given performance (distribution rate). For instance, in networks where only 80% of nodes operate as repeaters, well-performing topologies are able to retain over 90% of the distribution rate; whereas sparse, weakly connected graphs exhibit rapid performance degradation, retaining less than half of the distribution rate. Our results provide a topology-aware framework for protocol selection and infrastructure optimisation in future quantum networks, bridging routing design with cost-aware deployment strategies.

DOI
10.1364/JOCN.600057
Comments
10 pages, 14 figures, 4 tables

Related papers

Multiuser Entanglement Distribution in Quantum Networks Using Multipath Routing

Evan Sutcliffe, Alejandra Beghelli

Quantum networks facilitate numerous applications including secure communication and distributed quantum computation by performing entanglement distribution. For some multi-user quantum applications access to a shared multipartite state is required. We consider the problem of designing protocols for distributing such states, at an increased rate. For this, we propose three protocols that leverage multipath routing to increase the distribution rate for multi-user applications. The protocols are evaluated on quantum networks with NISQ constraints, including limited quantum memories and probabilistic entanglement generation. Simulation results show that the developed protocols achieve an exponential increase in the distribution rate of multipartite states compared to single path routing techniques, with a maximum increase of four orders of magnitude for the cases studied. Further, the relative increase in distribution rate was also found to improve for larger sets of users. When the protocols were tested in scaled-down real-world topologies, it was found that topology had a significant effect on the multipartite state distribution rates achieved by the protocols. Finally, we found that the benefits of multipath routing are maximum for short quantum memory decoherence times and intermediate values of entanglement generation probability. Hence, the protocols developed can benefit NISQ quantum network control and design.

arXiv:2303.03334•IEEE Transactions on Quantum Engineering•Jan 1, 2023•36 citations

Improved Routing of Multiparty Entanglement over Quantum Networks

Nirupam Basak, Goutam Paul

The effective routing of entanglement over a quantum network is a fundamental problem in quantum communication. The distribution and reshaping of multipartite entanglement over a quantum network requires scalable protocols that adapt to the underlying topology. Graph states provide a convenient framework for this challenging task, as they encode global entanglement in a structured way that can be locally manipulated to produce a variety of target states, without requiring additional long-distance quantum operations. In this article, we propose graph-state-based routing protocols for sharing GHZ states, achieving larger sizes than those achieved in the existing works for given network topologies. For this improvement, we consider tree structures connecting the users participating in the final GHZ states, as opposed to the linear configurations used in the earlier works. In particular, for grid networks, we show special constructions of such trees that achieve larger GHZ states than the prior works. Moreover, if the user nodes along which the entanglement is to be routed are pre-specified, a strategy is proposed to accomplish this routing.

arXiv:2409.14694•ACM Transactions on Quantum Computing•Apr 22, 2026•0 citations

On Designing A Quantum Network Topology: Model, Methodology, and Algorithm

Yuhang Gan, Ruilin Zhou, Shiyi Ling +2 more

Quantum networking has been attracting growing attention in both academia and industry during recent years. Although many routing protocols have been proposed to optimize the network layer of quantum networks, another key networklayer problem is under-explored: the topology design problem. Existing work is limited to using structure topologies such as a ring or grid, using randomly generated topologies, or using existing Internet backbone infrastructure. Whether these choices are desired for quantum networks is not fully explained. We propose the quantum network topology design problem, for which a set of end users are given and we need to compute a set of repeaters and their locations and connectivities while ensuring the network performance, such as throughput, is optimized under the same infrastructure cost (e.g., number of repeaters). We present the methodology of designing topologies based on the unique characteristics of entanglement distribution networks and propose an algorithm called TriPlace to compute a topology for a given set of end users in different locations of a geographic region. The simulation results show that TriPlace incurs a lower infrastructure cost than all existing solutions while achieving similar throughput performance as the best of these solutions. We believe this work will start a new research problem for quantum networks and attract more future work.

IEEE International Conference on Quantum Computing and Engineering (QCE)•Aug 30, 2025•0 citations

Asynchronous entanglement routing for the quantum internet

Zebo Yang, Ali Ghubaish, Raj Kumar Jain +2 more

With the emergence of the Quantum Internet, the need for advanced quantum networking techniques has significantly risen. Various models of quantum repeaters have been presented, each delineating a unique strategy to ensure quantum communication over long distances. We focus on repeaters that employ entanglement generation and swapping. This revolves around establishing remote end-to-end entanglement through repeaters, a concept we denote as the “quantum-native” repeaters (also called “first-generation” repeaters in some literature). The challenges in routing with quantum-native repeaters arise from probabilistic entanglement generation and restricted coherence time. Current approaches use synchronized time slots to search for entanglement-swapping paths, resulting in inefficiencies. Here, we propose a new set of asynchronous routing protocols for quantum networks by incorporating the idea of maintaining a dynamic topology in a distributed manner, which has been extensively studied in classical routing for lossy networks, such as using a destination-oriented directed acyclic graph or a spanning tree. The protocols update the entanglement-link topology asynchronously, identify optimal entanglement-swapping paths, and preserve unused direct-link entanglements. Our results indicate that asynchronous protocols achieve a larger upper bound with an appropriate setting and significantly higher entanglement rate than existing synchronous approaches, and the rate increases with coherence time, suggesting that it will have a much more profound impact on quantum networks as technology advances.

arXiv:2312.14300•AVS Quantum Science•Jan 18, 2024•31 citations

Efficient Multiparty Entanglement Distribution in Dynamic Quantum Networks

Roberto Negrin, Nicolas Dirnegger, William Munizzi +2 more

Distributing multipartite entanglement over a quantum network means routing it through a shared resource state. Existing measurement-based schemes search for a fresh path and re-verify the topology before every request, placing a network-wide classical exchange on the critical path of each one. We introduce DODAG-X, which removes it. A single destination-oriented directed acyclic graph spanning tree is computed once and reused across all requests, so each party's route is recovered by following parent pointers instead of by a new search. The per-request routing cost drops from $\mathcal{O}(N)$ to $\mathcal{O}(\sqrt{N})$ on symmetric grids and to $\mathcal{O}(\log N)$ on small-world networks for $N$ nodes, and only the $N-1$ tree links need be maintained under link loss. Routing on the sparse tree also shrinks the neighborhoods cleared to isolate the parties, lowering measurements per request by roughly 19\% on small-world graphs and up to 34\% on moderately dense, strongly rewired ones; on a fixed tree the two protocols use identical counts. We prove correctness for up to three parties with no restriction on topology, and prove a sufficient condition under which one application yields an $n$-party GHZ state for any $n$. We then delimit it, exhibiting requests outside the hypothesis whose output is multipartite entangled yet in a different local-Clifford class. Under a discrete-time Markov failure model the classical repair layer matches the reachability of full-graph re-search up to a failed-edge fraction of one half, and a coherence criterion relating tree depth to memory lifetime identifies the viable hardware platforms.

arXiv:2408.07118•Aug 13, 2024•0 citations

Quantum Entanglement Topological Network Routing

Jincheng Zhang

This paper proposes a novel distributed routing protocol for quantum networks leveraging the topological properties of quantum entanglement. The core idea is to construct a network topology based on entangled states between nodes, enabling communication through the instantaneous correlation inherent in entanglement. This approach aims to overcome the limitations of traditional routing protocols, particularly in terms of speed and security. We define a routing algorithm that dynamically adjusts the entanglement states to facilitate data transmission, effectively creating a network with inherently high bandwidth and resilience to eavesdropping. The algorithm is based on a graph theory framework where nodes represent quantum devices and edges represent entangled pairs. The routing process involves identifying the shortest path through the entanglement network, leveraging the correlated states for rapid information transfer. We explore the mathematical underpinnings of this protocol, outlining key formulas for calculating entanglement metrics, path distances, and routing decisions. The theoretical framework presented here provides a foundation for future research and development in quantum network architecture and routing strategies.

•Sep 6, 2026•0 citations
Quantum networks will rely on entanglement distribution to enable multi-user applications such as distributed quantum computing and cryptography. While multipartite entanglement distribution routing protocols have been extensively studied on idealised grid topologies, less is understood about how real network structure shapes their performance and resource requirements.
We present a systematic study of four routing protocols for multipartite entanglement distribution, each characterised by the number of paths (single-path and multi-path) and routing strategy (star-based and tree-based), over 81 real network topologies. We identified four distinct topology-dependent performance regimes, where: (i) all protocols perform poorly, (ii) tree-based protocols dominate, (iii) multi-path protocols dominate, or (iv) all protocols perform well. By correlating clusters with graph metrics, we also provide structural explanations for the varied performance of specific protocols.
Additionally, motivated by the anticipated high cost of repeaters, we investigated the impact of repeater trimming on the performance of multi-path protocols. Topology strongly governs how far repeater nodes can be removed from the network while maintaining a given performance (distribution rate). For instance, in networks where only 80% of nodes operate as repeaters, well-performing topologies are able to retain over 90% of the distribution rate; whereas sparse, weakly connected graphs exhibit rapid performance degradation, retaining less than half of the distribution rate.
Our results provide a topology-aware framework for protocol selection and infrastructure optimisation in future quantum networks, bridging routing design with cost-aware deployment strategies.
Quantum networks facilitate numerous applications including secure communication and distributed quantum computation by performing entanglement distribution. For some multi-user quantum applications access to a shared multipartite state is required. We consider the problem of designing protocols for distributing such states, at an increased rate. For this, we propose three protocols that leverage multipath routing to increase the distribution rate for multi-user applications. The protocols are evaluated on quantum networks with NISQ constraints, including limited quantum memories and probabilistic entanglement generation. Simulation results show that the developed protocols achieve an exponential increase in the distribution rate of multipartite states compared to single path routing techniques, with a maximum increase of four orders of magnitude for the cases studied. Further, the relative increase in distribution rate was also found to improve for larger sets of users. When the protocols were tested in scaled-down real-world topologies, it was found that topology had a significant effect on the multipartite state distribution rates achieved by the protocols. Finally, we found that the benefits of multipath routing are maximum for short quantum memory decoherence times and intermediate values of entanglement generation probability. Hence, the protocols developed can benefit NISQ quantum network control and design.
The effective routing of entanglement over a quantum network is a fundamental problem in quantum communication. The distribution and reshaping of multipartite entanglement over a quantum network requires scalable protocols that adapt to the underlying topology. Graph states provide a convenient framework for this challenging task, as they encode global entanglement in a structured way that can be locally manipulated to produce a variety of target states, without requiring additional long-distance quantum operations. In this article, we propose graph-state-based routing protocols for sharing GHZ states, achieving larger sizes than those achieved in the existing works for given network topologies. For this improvement, we consider tree structures connecting the users participating in the final GHZ states, as opposed to the linear configurations used in the earlier works. In particular, for grid networks, we show special constructions of such trees that achieve larger GHZ states than the prior works. Moreover, if the user nodes along which the entanglement is to be routed are pre-specified, a strategy is proposed to accomplish this routing.
Quantum networking has been attracting growing attention in both academia and industry during recent years. Although many routing protocols have been proposed to optimize the network layer of quantum networks, another key networklayer problem is under-explored: the topology design problem. Existing work is limited to using structure topologies such as a ring or grid, using randomly generated topologies, or using existing Internet backbone infrastructure. Whether these choices are desired for quantum networks is not fully explained. We propose the quantum network topology design problem, for which a set of end users are given and we need to compute a set of repeaters and their locations and connectivities while ensuring the network performance, such as throughput, is optimized under the same infrastructure cost (e.g., number of repeaters). We present the methodology of designing topologies based on the unique characteristics of entanglement distribution networks and propose an algorithm called TriPlace to compute a topology for a given set of end users in different locations of a geographic region. The simulation results show that TriPlace incurs a lower infrastructure cost than all existing solutions while achieving similar throughput performance as the best of these solutions. We believe this work will start a new research problem for quantum networks and attract more future work.
With the emergence of the Quantum Internet, the need for advanced quantum networking techniques has significantly risen. Various models of quantum repeaters have been presented, each delineating a unique strategy to ensure quantum communication over long distances. We focus on repeaters that employ entanglement generation and swapping. This revolves around establishing remote end-to-end entanglement through repeaters, a concept we denote as the “quantum-native” repeaters (also called “first-generation” repeaters in some literature). The challenges in routing with quantum-native repeaters arise from probabilistic entanglement generation and restricted coherence time. Current approaches use synchronized time slots to search for entanglement-swapping paths, resulting in inefficiencies. Here, we propose a new set of asynchronous routing protocols for quantum networks by incorporating the idea of maintaining a dynamic topology in a distributed manner, which has been extensively studied in classical routing for lossy networks, such as using a destination-oriented directed acyclic graph or a spanning tree. The protocols update the entanglement-link topology asynchronously, identify optimal entanglement-swapping paths, and preserve unused direct-link entanglements. Our results indicate that asynchronous protocols achieve a larger upper bound with an appropriate setting and significantly higher entanglement rate than existing synchronous approaches, and the rate increases with coherence time, suggesting that it will have a much more profound impact on quantum networks as technology advances.
Distributing multipartite entanglement over a quantum network means routing it through a shared resource state. Existing measurement-based schemes search for a fresh path and re-verify the topology before every request, placing a network-wide classical exchange on the critical path of each one. We introduce DODAG-X, which removes it. A single destination-oriented directed acyclic graph spanning tree is computed once and reused across all requests, so each party's route is recovered by following parent pointers instead of by a new search. The per-request routing cost drops from O(N)\mathcal{O}(N)O(N) to O(N)\mathcal{O}(\sqrt{N})O(N​) on symmetric grids and to O(log⁡N)\mathcal{O}(\log N)O(logN) on small-world networks for NNN nodes, and only the N−1N-1N−1 tree links need be maintained under link loss. Routing on the sparse tree also shrinks the neighborhoods cleared to isolate the parties, lowering measurements per request by roughly 19\% on small-world graphs and up to 34\% on moderately dense, strongly rewired ones; on a fixed tree the two protocols use identical counts. We prove correctness for up to three parties with no restriction on topology, and prove a sufficient condition under which one application yields an nnn-party GHZ state for any nnn. We then delimit it, exhibiting requests outside the hypothesis whose output is multipartite entangled yet in a different local-Clifford class. Under a discrete-time Markov failure model the classical repair layer matches the reachability of full-graph re-search up to a failed-edge fraction of one half, and a coherence criterion relating tree depth to memory lifetime identifies the viable hardware platforms.
This paper proposes a novel distributed routing protocol for quantum networks leveraging the topological properties of quantum entanglement. The core idea is to construct a network topology based on entangled states between nodes, enabling communication through the instantaneous correlation inherent in entanglement. This approach aims to overcome the limitations of traditional routing protocols, particularly in terms of speed and security. We define a routing algorithm that dynamically adjusts the entanglement states to facilitate data transmission, effectively creating a network with inherently high bandwidth and resilience to eavesdropping. The algorithm is based on a graph theory framework where nodes represent quantum devices and edges represent entangled pairs. The routing process involves identifying the shortest path through the entanglement network, leveraging the correlated states for rapid information transfer. We explore the mathematical underpinnings of this protocol, outlining key formulas for calculating entanglement metrics, path distances, and routing decisions. The theoretical framework presented here provides a foundation for future research and development in quantum network architecture and routing strategies.