Optimal Rate for Constant-Fidelity Entanglement in Quantum Communication Networks

Kenneth Goodenough, Stephanie Wehner, David Elkouss

Tan Bacinoglu, Burhan Gülbahar, Özgür B. Akan

Entanglement distribution over long distances is one of the main problems in the existing quantum communication networks. Most of the existing methods of establishing entanglement paired link (Einstein, Podolsky, Rosen - EPR pairs) between distant nodes assume symmetric network topologies comprised of links with identical EPR generation capacities. In this work, the entanglement rate capacity of randomly distributed quantum ad hoc networks is investigated. To this end, constant fidelity maximum flow (CFMF) of entanglement problem is defined, and its theoretical analysis is presented. A new heuristic algorithm, i.e., Entanglement Swapping Scheme Search (ESSS), is presented to find the best possible swapping scheme over a multi-hop entanglement path. Furthermore, Shortest Path Entanglement Flow (SPEF) algorithm is introduced as an effective heuristic solution for this problem. Analysis shows that there is a trade-off between the desired constant target fidelity and the entanglement generation rate (maximum flow) of the network.

Zain Ali, Zouheir Rezki, Hamid R. Sadjadpour

The unbreakable security and higher data rates offered by quantum communication networks have made quantum communication an inevitable necessity of the future. Many quantum communication frameworks, such as quantum key distribution and super dense coding, require entangled pairs to be shared between the source and destination nodes. Communication nodes in quantum networks have a minimum fidelity requirement for the entangled pairs. If the fidelity requirement is not satisfied, the entangled pairs may not be used for the desired operations. Successful sharing of the entangled pairs between the nodes is a crucial step in making quantum communication practical. In this work, we propose a framework to maximize entanglement sharing between a source and multiple destination nodes in a fair manner. We consider a system that takes advantage of the purification process to improve the fidelity of the entangled pairs when necessary. The proposed solution framework provides the optimal number of entangled pairs required for the purification process and the optimal transmission rate at the source node to achieve the desired system objective. The non-convex problem is first transformed into a convex form, and then a Lagrangian dual-based framework is proposed to find the optimal solution values. Moreover, to optimize the number of entangled pairs for purification at each link, we derive a closed-form expression that provides the optimal value in a single step. Selected simulation results demonstrate that the proposed framework exhibits excellent performance.

Debarka Mukhopadhyay, Siddhartha Bhattacharyya, Jan Platoš +2 more

Jincheng Zhang

Quantum entanglement offers unparalleled security and information processing capabilities, but realizing this potential requires sophisticated quantum communication protocols. Current quantum communication networks often rely on pre-defined topologies, which can limit scalability and efficiency. This paper introduces a novel algorithm, "Adaptive Quantum Topology Optimization," designed to dynamically optimize the quantum entanglement network topology, thereby enhancing the efficiency and security of quantum communication. We propose a self-learning process that adjusts quantum entanglement parameters based on observed network performance, leading to more robust and adaptable quantum communication systems. This work addresses the limitations of traditional network design by providing a flexible and adaptive approach to topology optimization. We demonstrate the effectiveness of this algorithm through simulations, showcasing significant improvements in entanglement fidelity and communication rate compared to static topology configurations.

Yudai Ogata, Imran Ahmed, Eiji Oki