The use of quantum teleportation in future quantum networks creates a completely new way for communication. As the quantum link length increased, the fidelity decreased, owing to the loss of quantum information between distant quantum nodes. This paper conducts an exploration of quantum fidelity routing design that is intended to specifically focus on the applicability of quantum error correction (QEC) as the scale of the network expands. Our research involves proposing a novel Quantum-maximum Fidelity miNimum Dijkstra's (Q-FIND) algorithm incorporated with QEC, which is designed to not only improve the long-distance link fidelity, but also to further reduce the network latency under the conditions of a noisy quantum channel. By using Qiskit, we examine the performance of proposed routing algorithm. Our simulation result reveals that the significance of QEC becomes more prominent in long-distance quantum networks.
The use of quantum teleportation in future quantum networks creates a completely new way for communication. As the quantum link length increased, the fidelity decreased, owing to the loss of quantum information between distant quantum nodes. This paper conducts an exploration of quantum fidelity routing design that is intended to specifically focus on the applicability of quantum error correction (QEC) as the scale of the network expands. Our research involves proposing a novel Quantum-maximum Fidelity miNimum Dijkstra's (Q-FIND) algorithm incorporated with QEC, which is designed to not only improve the long-distance link fidelity, but also to further reduce the network latency under the conditions of a noisy quantum channel. By using Qiskit, we examine the performance of proposed routing algorithm. Our simulation result reveals that the significance of QEC becomes more prominent in long-distance quantum networks.
Long-distance quantum networks are far more than mere channels for data transfer; they are sophisticated systems that harness the counterintuitive features of quantum mechanics to enable secure and high-performance communication over vast distances. In our study, we explore the underlying mechanisms of quantum connectivity by investigating phenomena such as superposition and entanglement, and their roles in sustaining robust information propagation. We focus on the interaction between these quantum effects and routing protocols strategies that, while inspired by classical networks, must overcome challenges associated with quantum decoherence and measurement uncertainty. To evaluate these interactions, we simulated distributed quantum networks with node counts ranging from 10 to 100 using novel routing strategies including Q-Learning, Bell State, and Entanglement Swapping protocols. Our analysis centers on key performance metrics that capture both quantum fidelity and operational efficiency. Notably, our results show that high quantum state fidelity is maintained across all network configurations, confirming the efficacy of entangled states in preserving the integrity of quantum information over long distances. Simultaneously, we observe that increased network complexity introduces trade-offs, such as higher computational overhead and amplified susceptibility to decoherence and error propagation. These findings underscore the necessity for advanced error-correction techniques and adaptive routing strategies to ensure scalability and robustness in long-distance quantum communication. Overall, our work provides critical insights into optimizing quantum superposition and entanglement in practical routing implementations, thereby paving the way for the future realization of a global quantum communication infrastructure.
Future quantum networks will enable the interconnection of multiple users distributed across vast geographic distances. Due to these large separations and limited physical resources, communication will often rely on multi-path routing strategies, where physical resources are distributed across channels of varying lengths and delivered to end users. Efficient long-distance quantum communication therefore requires optimizing the allocation of these resources across available paths. In this work, we introduce a performance-oriented approach to quantum network routing by extending the classical concept of Quality of Service (QoS) to the context of multi-path quantum resources distribution. Unlike prior models that consider entanglement generation or quantum memory coherence in isolation, we investigate the interplay between path assignment strategies, coherence time constraints, and quantum error correction (QEC), and how they jointly impact end-to-end communication fidelity. We analyze both unencoded and encoded transmissions over aggregated network paths, quantifying the effects of resource allocation on transmission success. Our findings show that fidelity cannot be optimized independently of memory lifetimes, and that while QEC can enhance performance under specific conditions, it also imposes additional constraints depending on network topology and path-length asymmetries. This work provides a foundation for developing QoS-aware quantum routing protocols that balance fidelity, throughput, and memory utilization -- key considerations for near-term quantum repeater networks.
Entanglement routing establishes remote entanglement connection between two arbitrary nodes, which is one of the most important functions in quantum networks. The existing routing mechanisms mainly improve the robustness and throughput facing the failure of entanglement generations, which, however, rarely include the considerations on the most important metric to evaluate the quality of connection, entanglement fidelity. To solve this problem, we propose purification-enabled entanglement routing designs to provide fidelity guarantee for multiple Source-Destination (SD) pairs in quantum networks. In our proposal, we first consider the single S-D pair scenario and design an iterative routing algorithm, Q-PATH, to find the optimal purification decisions along the routing path with minimum entangled pair cost. Further, a low-complexity routing algorithm using an extended Dijkstra algorithm, Q-LEAP, is designed to reduce the computational complexity by using a simple but effective purification decision method. Then we consider the common scenario with multiple S-D pairs and design a greedy-based algorithm considering resource allocation and rerouting process for multiple routing requests. To verify the effectiveness and superiority of the proposed algorithms, extensive simulations are conducted, and the simulation results show that the proposed algorithms not only can provide fidelity-guarantee routing solutions, but also has superior performance in terms of throughput, fidelity of end-to-end entanglement connection, and resource utilization ratio, compared with the existing routing scheme.
The scalability of quantum communication networks is crucial for enabling secure information exchange and distributed quantum computing across global infrastructures. However, achieving scalability remains a significant challenge due to the effects of decoherence, photon loss, and fidelity degradation over extended distances. This paper performs a critical investigation into the scalability limits of quantum communication networks, focusing on the interplay between entanglement generation rates, end-to-end fidelity, and network parameters such as node separation, noise levels, and total distance. Leveraging the SeQUeNCe simulation framework, we model adaptable trapped-ion repeater networks to uncover fundamental insights into both homogeneous and heterogeneous configurations. Our findings reveal transformative insights that help reshape system designs for near term quantum networks. We identify maximum node separation thresholds critical for practical implementations, illuminate the non-linear degradation of fidelity with increasing distance, and expose how routing and swapping protocols influence entanglement success rates at scale. Most notably, we demonstrate that while additional repeaters can mitigate distance-induced failures, excessive node counts introduce compounding fidelity losses that threaten network viability under certain architectures. These results provide a roadmap for revolutionizing quantum networks, with actionable design strategies such as optimized node placement, advanced routing algorithms, and the adoption of cutting-edge qubit technologies like topological qubits. By addressing key bottlenecks in quantum communication scalability, our work lays the foundation for the next generation of global quantum networks.
Entanglement routing establishes remote entanglement connection between two arbitrary nodes, which is one of the most important functions in quantum networks. The existing routing mechanisms mainly improve the robustness and throughput facing the failure of entanglement generations, which, however, rarely include the considerations on the most important metric to evaluate the quality of connection, entanglement fidelity. To solve this problem, we propose purification-enabled entanglement routing designs to provide fidelity guarantee for multiple Source-Destination (S-D) pairs in quantum networks. In our proposal, we first consider the single S-D pair scenario and design an iterative routing algorithm, Q-PATH, to find the optimal purification decisions along the routing path with minimum entangled pair cost. Further, a low-complexity routing algorithm using an extended Dijkstra algorithm, Q-LEAP, is designed to reduce the computational complexity by using a simple but effective purification decision method. Finally, we consider the common scenario with multiple S-D pairs and design a greedy-based algorithm considering resource allocation and re-routing process for multiple routing requests. Simulation results show that the proposed algorithms not only can provide fidelity-guaranteed routing solutions, but also has superior performance in terms of throughput, fidelity of end-to-end entanglement connection, and resource utilization ratio, compared with the existing routing scheme.
This paper explores the optimization of multi-path communication within quantum networks, aiming to enhance communication efficiency and reliability. The core concept involves distributing quantum information across multiple paths and employing an optimized algorithm to manage this distribution. The algorithm focuses on minimizing latency, maximizing throughput, and mitigating the effects of channel loss inherent in quantum communication. We present a novel approach utilizing a layered optimization strategy, combining shortest path routing with adaptive power allocation. Mathematical formulations are detailed, including metrics for path quality, latency, and overall network throughput. The proposed method offers a significant improvement over traditional single-path communication strategies, particularly in complex quantum network topologies. Simulation results (though not presented through experimental data) demonstrate a substantial increase in communication performance under various network conditions. Further research will explore integration with quantum error correction codes and dynamic network topology adaptation.