Topology adaption for the quantum Internet

László Gyöngyösi, Sándor Imre

Peter P. Rohde

Maoli Liu, Zhuohua Li, Kechao Cai +3 more

Large-scale quantum networks with thousands of nodes require topology-oblivious routing protocols to realize. Most existing quantum network routing protocols only consider the intra-domain scenario, where all nodes belong to a single party with complete topology knowledge. However, like the classical Internet, quantum Internet will likely be provided by multiple quantum Internet Service Providers (qISPs). In this paper, we consider the inter-domain scenario, where the network consists of multiple subnetworks owned by mutually untrusted parties without centralized control. Under this setting, previously proposed quantum entanglement routing policies, which rely on the network topology knowledge, are no longer applicable. We propose a Quantum Border Gateway Protocol (QBGP) for efficiently routing entanglement across qISP boundaries. To guarantee high-quality information transmission, we propose an algorithm named online top-K path selection. This algorithm utilizes the information gain introduced in this paper to adaptively decide on measurement parameters, allowing for the selection of high-fidelity paths and accurate fidelity estimates, while minimizing costs. Additionally, we implement a quantum network simulator and evaluate our protocol and algorithm. Our evaluation shows that QBGP effectively distributes entanglement across different qISPs, and our path selection algorithm increases the network performance by selecting high-fidelity paths with much lower resource consumption than other methods.

Stephanie Wehner

Ruozhou Yu, Rudra Dutta, Jianqing Liu

Imagine a Quantum Internet where people can freely establish physically secure communication channels or migrate quantum programs between anywhere in the world. What would it look like? Despite the very exciting recent advances around building prototypes of quantum networks, little is known about how lab-scale prototypes can be expanded into a global infrastructure that is as capacitated, robust, and cost-efficient as the digital Internet right now. Part of the difficulty lies in our lack of understanding of how the structure of a quantum network affects its capacity and performance when serving multi-commodity quantum communication demands. This article studies the problem of designing high-performance network topologies for the quantum Internet. Utilizing abstract models of the basic quantum network operations and an optimal entanglement distribution protocol, we characterize the capacity and performance of various candidate topologies for the quantum Internet, in terms of the rate of entanglement distribution between source-destination pairs and the fidelity of entangled pairs, respectively. We discuss the implications of our preliminary results, and propose directions for further investigation. As the feasibility of largescale quantum network deployment continues to increase, we hope this article can draw attention to these macroscopic design problems, such as topology design, which potentially have a profound influence on how the entire technology evolves, just as we have observed with the digital Internet in the past decades.

Louis Hirsch Kauffman, Samuel J. Lomonaco