Effective routing design for remote entanglement generation on quantum networks

Abstract

Quantum network is a promising platform for many ground-breaking applications that lie beyond the capability of its classical counterparts. Efficient entanglement generation on quantum networks with relatively limited resources such as quantum memories is essential to fully realize the network’s capabilities, the solution to which calls for delicate network design and is currently at the primitive stage. In this study we propose an effective routing scheme to enable automatic responses for multiple requests of entanglement generation between source-terminal stations on a quantum lattice network with finite edge capacities. Multiple connection paths are exploited for each connection request while entanglement fidelity is ensured for each path by performing entanglement purification. The routing scheme is highly modularized with a flexible nature, embedding quantum operations within the algorithmic workflow, whose performance is evaluated from multiple perspectives. In particular, three algorithms are proposed and compared for the scheduling of capacity allocation on the edges of quantum network. Embodying the ideas of proportional share and progressive filling that have been well-studied in classical routing problems, we design another scheduling algorithm, the propagatory update method, which in certain aspects overrides the two algorithms based on classical heuristics in scheduling performances. The general solution scheme paves the road for effective design of efficient routing and flow control protocols on applicational quantum networks.

Policies for elementary links in a quantum network

“…Typically, these works have been focused primarily on the topology of a linear chain of nodes. However, more recent work [66,78,79,[114][115][116][117][118][119][120][121][122][123] has begun to focus on arbitrary topologies, with routing protocols taken into account in some cases [56,57,89,90,[124][125][126][127]. The techniques used in these works are often varied, and sometimes different terminology and mathematical tools are used.…”

DQRA: Deep Quantum Routing Agent for Entanglement Routing in Quantum Networks

“…There are high demands of network resources and security in today's network and the next-generation network systems since more and more devices are connected to the Internet and new services are created. Quantum network appears as a promising technology to enhance exchanged information security via the Internet [1], [2], [3], [4]. With recent advances in quantum computing technology [5], [6], [7], [8], [9], a quantum network is built upon the conventional network (e.g., network slicing) that is composed by various nodes (computers) equipped with quantum processors to process and deliver information in the form of quantum bits, called qubits [1], [2], [10], [11].…”

Fidelity-Guarantee Entanglement Routing in Quantum Networks

“…As shown in Fig. 1, to establish such end-to-end entanglement connection, entangled pairs between adjacent nodes are first generated in the network, then quantum repeater connects quantum nodes over longer distances by performing entanglement swapping, i.e., joint Bell state measurements at the local repeater aided by classical communication [8]. In the future, to build up a largescale functional quantum network and satisfy the dynamic requests from multiple Source-Destination (S-D) pairs, one critical problem is how to select routing path of entanglement connection and utilize the network resources efficiently (such as limited entangled pairs on each edge).…”

“…In the future, to build up a largescale functional quantum network and satisfy the dynamic requests from multiple Source-Destination (S-D) pairs, one critical problem is how to select routing path of entanglement connection and utilize the network resources efficiently (such as limited entangled pairs on each edge). In recent years, some existing works are dedicated to solve such problem, and propose multiple entanglement routing designs [6,8,9] to improve the robustness and throughput facing the failure of entanglement generations. Although the development of quantum network is currently at the primitive stage, these routing designs bring a good start to facilitate the process of quantum networks' construction in the future.…”

“…In practical, due to the noise in the system, quantum repeaters sometimes might not generate entangled pairs with a certain desired fidelity, which brings negative effects on various quantum applications. For example, in quantum cryptography protocols (e.g., BB84 protocol), an entanglement fidelity lower than the quantum bit error rate can reduce the security of key distribution [8]. To improve the fidelity of entanglement connection and satisfy the requirement of quantum applications, a technique called entanglement purification can be used to increase the fidelity of entangled pairs, it consumes shared lower-fidelity entangled pairs along the link between adjacent nodes to obtain one target higher-fidelity entangled pair.…”