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:2407.11376 · IEEE International Conference on Quantum Computing and Engineering (QCE)

Analytical Performance Estimations for Quantum Repeater Network Scenarios

Allen Zang, Joaquín Chung, Rajkumar Kettimuthu, Martin Suchara, Tian Zhong

Published Sep 15, 2024• 6 citations
arXivHTMLPDF

Abstract

Quantum repeater chains will form the backbone of future quantum networks that distribute entanglement between network nodes. Therefore, it is important to understand the entanglement distribution performance of quantum repeater chains, especially their throughput and latency. By using Markov chains to model the stochastic dynamics in quantum repeater chains, we offer analytical estimations for long-run throughput and on-demand latency of continuous entanglement distribution. We first study single-link entanglement generation using general multiheralded protocols. We then model entanglement distribution with entanglement swapping over two links, using either a single- or a double-heralded entanglement generation protocol. We also demonstrate how the two-link results offer insights into the performance of general$2^{k}$-link nested repeater chains. Our results enrich the quantitative understanding of quantum repeater network performance, especially the dependence on system parameters. The analytical formulae themselves are valuable reference resources for the quantum networking community. They can serve as benchmarks for quantum network simulation validation or as examples of quantum network dynamics modeling using the Markov chain formalism.

DOI
10.1109/qce60285.2024.00226

Related papers

Entanglement Swapping Scheduling for Quantum Repeater Chains under Decoherence during Classical Communications

Jorge Benito Díaz, Andrés Agustí, Jabier Faba +3 more

First-generation quantum repeaters are essential in distributing entanglement over long distances since they could mitigate losses in optical fiber. Repeaters split the total distance into shorter, easier to generate links. Then, entanglement swapping establishes long range entanglement by performing local measurements at the repeaters and heralding their results. In this work, we develop an analytical model that estimates the impact of decoherence during heralding for a given protocol. Furthermore, we identify a competition between two phenomena: as repeater count increases, so does entanglement generation, but the additive impact of memory decoherence on final entanglement rate increases too. Therefore, we find that an optimal number of repeaters exists. These findings could lead the design of future quantum networks, both in the inter-repeater distance and swapping timings.

quant-pharXiv:2610.07991•Oct 7, 2026•0 citations

On the Analysis of Quantum Repeater Chains with Sequential Swaps

Matheus Guedes de Andrade, Emily A. Van Milligen, Leonardo Bacciottini +5 more

We evaluate the performance of two-way quantum repeater chains with sequential entanglement swapping. Within the analysis we consider memory decoherence, gate imperfections, and imperfect link-level entanglement generation. Our main results include closed-form expressions for the average entanglement fidelity of the generated end-to-end entangled states. We generalize previous findings for the one-shot fidelity analysis and study the case where repeater chains serve end-to-end requests continuously. We provide solutions to the continuous request scenario by combining results from quantum information theory and queuing theory. Finally, we apply the formulas obtained to analyze the impacts of hardware parameters, i.e., coherence times and gate fidelity, and distance on the entanglement fidelity and secret key rate of homogeneous quantum repeater chains.

arXiv:2405.18252•May 28, 2024•2 citations

End-to-End Entanglement Distribution Rate Approximation over Quantum Repeater Chains

Gargi Donde, Jiyao Liu, Yu Wang

Entanglement distribution rate (EDR) is a fundamental performance metric for quantum networks. Existing EDR models often focus on expected throughput, but expectation alone is insufficient for Quality-of-Service (QoS)-aware provisioning, where a network must satisfy user demands with a specified probability rather than only on average. This paper studies the distribution of end-to-end EDR over linear quantum repeater chains. Existing works for exact distribution calculation becomes computationally expensive as chain width and length increase. To overcome this, we develop a moment-based analytical approximation that represents each intermediate segment throughput as a Gaussian distribution with matched mean and variance. The algorithm runs in O(L) time for a chain of length L while retaining the accuracy of cumulative distribution information needed for QoS probability queries. Evaluations against exact recursive computation show that the approximation preserves the main throughput trends, achieves speedups up to 6,000×, and maintains modest distributional error in the tested regimes. These results demonstrate that the proposed approximation provides an efficient analytical foundation for QoS-aware EDR analysis and future optimization of quantum repeater chains.

•Aug 17, 2026•0 citations

Performance Enhancement in Quantum Repeater Chains via Simultaneous Entanglement Swappings

Javier Faba, Andrés Agustí Casado, Luis Robledo +1 more

In this work, we study the performance of simultaneous—also referred to as parallel—entanglement swapping strategies through the average entanglement of formation of the resulting Werner states shared between the end nodes. As an application of our analytical extension of the quantum network model, we analyze a simple four-node quantum repeater chain to compare both parallel and non-parallel strategies. Although parallel entanglement swapping strategies exhibit lower success probabilities, they outperform non-parallel ones when decoherence and entanglement measures are taken into account. These results indicate that parallel entanglement swapping processes can significantly enhance the performance of entanglement distribution networks, suggesting that they could play a key role in the design of future quantum network architectures.

International Conference on Quantum Communications, Networking, and Computing (QCNC)•Apr 6, 2026•0 citations

Stochastic Multipath Routing for High-Throughput Entanglement Distribution in Quantum Repeater Networks

Ankit Mishra, Kang Hao Cheong

Quantum repeater networks distribute entanglement over lossy links while many users share a limited pool of entangled pairs. Most existing routing schemes either always use a single best path or rely on global optimizations that are hard to run in real time. Here we propose and analyze a simple alternative: a stochastic multipath rule in which each entanglement request is sent at random along one of several edge-disjoint repeater paths, with a single parameter that controls the bias between shorter and longer routes. Using a distance-dependent lossy network model with finite per-link capacities and probabilistic entanglement swapping, we develop an analytic description of the resulting end-to-end entanglement rate as a function of this bias and validate it with large-scale numerical simulations. We find that an intermediate bias consistently outperforms both deterministic extremes across distances, traffic patterns, attenuation, swapping noise, and congestion, bringing the rate close to simple capacity upper bounds and making link usage more even across networks. These results identify stochastic multipath routing as a lightweight classical control strategy for boosting performance and scalability in near-term quantum repeater networks.

quant-pharXiv:2603.25563•Mar 27, 2026•0 citations

Single-Satellite Quantum Repeater Performance Analysis

Cameron Paterson, Jasminder S. Sidhu, Thomas Brougham +2 more

Satellite optical links may be able to extend quantum communication range beyond that which is possible through optical fibres which are constrained by exponential loss scaling. Quantum repeaters have been proposed to mitigate high channel losses in both fibre and satellite links. Although satellite quantum repeaters could improve entanglement distribution efficiency, the attempt rate is constrained by classical communication latency in the entanglement swapping step. Direct entanglement distribution does not suffer this latency and can therefore compensate for high dual-downlink losses by increasing the source rate. A systematic comparative analysis of repeater-assisted and direct entanglement distribution rates using a satellite is absent from the literature. In addition to entanglement distribution rates, a detailed analysis of the fidelity of entanglement distributed by repeater-assisted satellite links has yet to be performed. Here, we develop an in-depth framework for describing a space quantum link consisting of a single satellite and two ground stations. We compare the entanglement distribution rates of direct and repeater-assisted satellite entanglement distribution, taking into account variations in overpass geometry and quantum memory capacity. The long-term entanglement distribution performance to different pairs of major cities is also considered, and the altitudinal dependence is explored. Furthermore, we develop a Monte Carlo model of the repeater satellite to explore the effect that different memory management policies and capacities have on the waiting time statistics of memory qubits. From these statistics we calculate the fidelity distributions of the entangled pairs established between the ground stations. These results will inform mission design for future space-borne quantum repeater nodes, as well as requirements on space-based memory platforms.

quant-pharXiv:2604.16165•Apr 20, 2026•0 citations
Quantum repeater chains will form the backbone of future quantum networks that distribute entanglement between network nodes. Therefore, it is important to understand the entanglement distribution performance of quantum repeater chains, especially their throughput and latency. By using Markov chains to model the stochastic dynamics in quantum repeater chains, we offer analytical estimations for long-run throughput and on-demand latency of continuous entanglement distribution. We first study single-link entanglement generation using general multiheralded protocols. We then model entanglement distribution with entanglement swapping over two links, using either a single- or a double-heralded entanglement generation protocol. We also demonstrate how the two-link results offer insights into the performance of general2k2^{k}2k-link nested repeater chains. Our results enrich the quantitative understanding of quantum repeater network performance, especially the dependence on system parameters. The analytical formulae themselves are valuable reference resources for the quantum networking community. They can serve as benchmarks for quantum network simulation validation or as examples of quantum network dynamics modeling using the Markov chain formalism.
First-generation quantum repeaters are essential in distributing entanglement over long distances since they could mitigate losses in optical fiber. Repeaters split the total distance into shorter, easier to generate links. Then, entanglement swapping establishes long range entanglement by performing local measurements at the repeaters and heralding their results. In this work, we develop an analytical model that estimates the impact of decoherence during heralding for a given protocol. Furthermore, we identify a competition between two phenomena: as repeater count increases, so does entanglement generation, but the additive impact of memory decoherence on final entanglement rate increases too. Therefore, we find that an optimal number of repeaters exists. These findings could lead the design of future quantum networks, both in the inter-repeater distance and swapping timings.
We evaluate the performance of two-way quantum repeater chains with sequential entanglement swapping. Within the analysis we consider memory decoherence, gate imperfections, and imperfect link-level entanglement generation. Our main results include closed-form expressions for the average entanglement fidelity of the generated end-to-end entangled states. We generalize previous findings for the one-shot fidelity analysis and study the case where repeater chains serve end-to-end requests continuously. We provide solutions to the continuous request scenario by combining results from quantum information theory and queuing theory. Finally, we apply the formulas obtained to analyze the impacts of hardware parameters, i.e., coherence times and gate fidelity, and distance on the entanglement fidelity and secret key rate of homogeneous quantum repeater chains.
Entanglement distribution rate (EDR) is a fundamental performance metric for quantum networks. Existing EDR models often focus on expected throughput, but expectation alone is insufficient for Quality-of-Service (QoS)-aware provisioning, where a network must satisfy user demands with a specified probability rather than only on average. This paper studies the distribution of end-to-end EDR over linear quantum repeater chains. Existing works for exact distribution calculation becomes computationally expensive as chain width and length increase. To overcome this, we develop a moment-based analytical approximation that represents each intermediate segment throughput as a Gaussian distribution with matched mean and variance. The algorithm runs in O(L) time for a chain of length L while retaining the accuracy of cumulative distribution information needed for QoS probability queries. Evaluations against exact recursive computation show that the approximation preserves the main throughput trends, achieves speedups up to 6,000×, and maintains modest distributional error in the tested regimes. These results demonstrate that the proposed approximation provides an efficient analytical foundation for QoS-aware EDR analysis and future optimization of quantum repeater chains.
In this work, we study the performance of simultaneous—also referred to as parallel—entanglement swapping strategies through the average entanglement of formation of the resulting Werner states shared between the end nodes. As an application of our analytical extension of the quantum network model, we analyze a simple four-node quantum repeater chain to compare both parallel and non-parallel strategies. Although parallel entanglement swapping strategies exhibit lower success probabilities, they outperform non-parallel ones when decoherence and entanglement measures are taken into account. These results indicate that parallel entanglement swapping processes can significantly enhance the performance of entanglement distribution networks, suggesting that they could play a key role in the design of future quantum network architectures.
Quantum repeater networks distribute entanglement over lossy links while many users share a limited pool of entangled pairs. Most existing routing schemes either always use a single best path or rely on global optimizations that are hard to run in real time. Here we propose and analyze a simple alternative: a stochastic multipath rule in which each entanglement request is sent at random along one of several edge-disjoint repeater paths, with a single parameter that controls the bias between shorter and longer routes. Using a distance-dependent lossy network model with finite per-link capacities and probabilistic entanglement swapping, we develop an analytic description of the resulting end-to-end entanglement rate as a function of this bias and validate it with large-scale numerical simulations. We find that an intermediate bias consistently outperforms both deterministic extremes across distances, traffic patterns, attenuation, swapping noise, and congestion, bringing the rate close to simple capacity upper bounds and making link usage more even across networks. These results identify stochastic multipath routing as a lightweight classical control strategy for boosting performance and scalability in near-term quantum repeater networks.
Satellite optical links may be able to extend quantum communication range beyond that which is possible through optical fibres which are constrained by exponential loss scaling. Quantum repeaters have been proposed to mitigate high channel losses in both fibre and satellite links. Although satellite quantum repeaters could improve entanglement distribution efficiency, the attempt rate is constrained by classical communication latency in the entanglement swapping step. Direct entanglement distribution does not suffer this latency and can therefore compensate for high dual-downlink losses by increasing the source rate. A systematic comparative analysis of repeater-assisted and direct entanglement distribution rates using a satellite is absent from the literature. In addition to entanglement distribution rates, a detailed analysis of the fidelity of entanglement distributed by repeater-assisted satellite links has yet to be performed. Here, we develop an in-depth framework for describing a space quantum link consisting of a single satellite and two ground stations. We compare the entanglement distribution rates of direct and repeater-assisted satellite entanglement distribution, taking into account variations in overpass geometry and quantum memory capacity. The long-term entanglement distribution performance to different pairs of major cities is also considered, and the altitudinal dependence is explored. Furthermore, we develop a Monte Carlo model of the repeater satellite to explore the effect that different memory management policies and capacities have on the waiting time statistics of memory qubits. From these statistics we calculate the fidelity distributions of the entangled pairs established between the ground stations. These results will inform mission design for future space-borne quantum repeater nodes, as well as requirements on space-based memory platforms.