Journal of Optical Communications and Networking

Pre-established entanglement distribution algorithm in quantum networks

Yazi Wang, Xiaosong Yu, Yongli Zhao, Avishek Nag, Jie Zhang

Published Nov 15, 2022• 13 citations

Abstract

As the basic principle of quantum networks, quantum entanglement can enable important quantum applications such as teleportation and quantum-key distribution. To realize wide-area quantum communication, entanglement establishment between two remote communication parties is vital, and it requires effective entanglement distribution strategies. Entanglement distribution network models of distributed and centralized entangled pair sources are constructed, based on which two entanglement-distribution algorithms are proposed, i.e., the real-time entanglement distribution (R-TED) algorithm and the pre-established entanglement distribution (P-EED) algorithm, to achieve end-to-end multi-hop entanglement establishment. For the former, the objective is to build long-distance entanglements via hop-by-hop entanglement tentatively and entanglement swapping to finally glue them together. For the latter, which uses pre-established entanglement, entanglements can be established in advance to patch multiple link-level entanglements via entanglement swapping. Simulation results show that as the number of time slots increases, the P-EED algorithm is more efficient and has higher entanglement establishment probability than the R-TED algorithm to establish end-to-end entanglement; while there are fewer memory cells in a quantum memory, such as 10, the R-TED algorithm provides more stable entanglement distribution compared to the P-EED algorithm.

DOI: 10.1364/jocn.465432

Related papers

Time-Scheduled End-to-End Entanglement Establishment in Memory-Cell-Limited Quantum Networks

Yazi Wang, Xiaosong Yu, Yongli Zhao +3 more

Quantum entanglement enables quantum networks to provide end-to-end sharing of entangled particles, establishing multi-hop path-to-path connections between remote parties. Implementing entanglement distribution plays a vital role in increasing the network scale, and practical entanglement algorithms are required to provide end-to-end multi-hop quantum entanglement. We consider the real-time entanglement distribution (R-TED) and pre-established entanglement distribution (P-EED) to meet this requirement. Based on these two types of entanglement distribution, we propose two algorithms, i.e., R-TED-based routing and entangled pairs allocation (REA) algorithm as well as P-EED-based REA algorithm for end-to-end entanglement establishment, where the practical physical factors (e.g., finite storage capacity and limited storage time) are considered. The R-TED-based REA algorithm can orchestrate the nodes in a route and perform entanglement swapping by adopting real-time entanglement. For the P-EED-based REA algorithm, remote entangled particle sharing can be achieved via pre-shared entanglement distribution and hop-by-hop entanglement swapping. This way, the entanglement routing selection satisfies the storage time constraint and allows two far-apart nodes to share long-distance entangled particles with limited memory cells. We evaluate the performance of the proposed algorithms under different network topologies and sizes, based on which we demonstrate that the network size can significantly affect the efficiency advantage achieved by the P-EED-based approach over the R-TED-based approach.

IEEE Transactions on NetworkingApr 30, 20252 citations

Pre-established Entanglement Distribution with Time-Guaranteed Memory Cells Selection in Quantum Networks

Yazi Wang, Yongli Zhao, Xiaosong Yu +2 more

Quantum entanglement enables numerous quantum applications such as secure communication. Based on entanglement-based quantum networks, long-distance entanglement establishment between two distant end nodes is vital to realize practical quantum networks. However, due to the decoherence and imperfect quantum operations such as the non-determinism of entanglement swapping, the latency of remote entanglement distribution will be increased, simultaneously, ongoing quantum operations will be cut off caused by the short coherence time of quantum memory. In this article, we propose a pre-established entanglement distribution algorithm which contains a time-guaranteed memory cells selection algorithm, aiming to choose the maximum time-matching entangled particle in each node to establish end-to-end entanglement. Simulation results show that for the different scales of grid network topologies, all success probability values are increasing with increase the size of the memory cells and the size of the time slots. Considering constructing the large scale of quantum network, it's necessary to consider employing high multi-mode capability and long lifetime quantum memory.

IEEE International Conference on Communication Technology (ICCT)Nov 11, 20221 citation

Connection-Oriented and Connectionless Remote Entanglement Distribution Strategies in Quantum Networks

Zhonghui Li, Kaiping Xue, Jian Li +3 more

Quantum network is a promising platform for numerous quantum applications, including distributed quantum computing, secure communication, and improved sensing. Implementing entanglement distribution between remote quantum nodes plays a vital role in realizing the quantum network's capabilities, and it requires effective remote entanglement distribution protocols. To meet this requirement, we propose two strategies, namely connection-oriented and connectionless, to achieve end-to-end entanglement distribution inspired by the designs of classical communication. For the connection-oriented strategy, an exclusive quantum connection is pre-established between the source and destination nodes. For the connectionless strategy, entanglement swapping is performed hop-by-hop tentatively. In this way, the best-effort service is provided for the source node to establish long-distance entanglement with the destination node. Analogous to classical communication, the proposed strategies have their advantages and disadvantages. Our simulation results show that the connectionless strategy is more efficient and robust than the connection-oriented strategy in terms of throughput. However, the connection-oriented strategy provides reliable end-to-end entanglement distribution but at the expense of higher overhead. Moreover, the application scenarios of these two strategies are discussed. This work paves the road for designing end-to-end entanglement distribution protocols in quantum networks.

IEEE NetworkJul 25, 202225 citations

Concurrent Entanglement Routing for Quantum Networks

Shouqian Shi, Chen Qian

Quantum entanglement enables important computing applications such as quantum key distribution. Based on quantum entanglement, quantum networks are built to provide long-distance secret sharing between two remote communication parties. Establishing a multi-hop quantum entanglement exhibits a high failure rate, and existing quantum networks rely on trusted repeater nodes to transmit quantum bits. However, when the scale of a quantum network increases, it requires end-to-end multi-hop quantum entanglements in order to deliver secret bits without letting the repeaters know the secret bits. This work focuses on the entanglement routing problem, whose objective is to build long-distance entanglements via untrusted repeaters for concurrent source-destination pairs through multiple hops. Different from existing work that analyzes the traditional routing techniques on special network topologies, we present a comprehensive entanglement routing model that reflects the differences between quantum networks and classical networks as well as a new entanglement routing algorithm that utilizes the unique properties of quantum networks. Evaluation results show that the proposed algorithm Q-CAST increases the number of successful long-distance entanglements by a big margin compared to other methods. The model and simulator developed by this work may encourage more network researchers to study the entanglement routing problem.

ACM SIGCOMM Conference (SIGCOMM)Jul 30, 2020193 citations

Concurrent Entanglement Routing for Quantum Networks: Model and Designs

Shouqian Shi, Xiaoxue Zhang, Chen Qian

IEEE/ACM Transactions on NetworkingJan 5, 202471 citations

Modeling and Designing Routing Protocols in Quantum Networks

Shouqian Shi, Chen Qian

Quantum networks enable a number of important applications such as quantum key distribution. The basic function of a quantum network is to enable long-distance quantum entanglement between two remote communication parties. This work focuses on the entanglement routing problem, whose objective is to build long-distance entanglements for the concurrent source-destination pairs through multiple hops. Different from existing works that analyzes the traditional routing techniques on special network topologies, we present a comprehensive entanglement routing model that reflects the differences between quantum networks and classical networks and new entanglement routing algorithms that utilize the unique properties of quantum networks. Evaluation results show that the proposed algorithm Q-CAST increases the number of successful long-distance entanglements by a big margin compared to other methods. The model and simulator developed by this work may encourage more network researchers to study the entanglement routing problem.

arXiv:1909.09329Sep 20, 201911 citations