2018/05/31 by F. Hahn, A. Pappa, J. Eisert · 1 citation
Computer Science · Physics and Astronomy · #Bipartite graph #Bottleneck #Graph #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum computer #Quantum entanglement #Quantum network #Repeater (horology) #quant-ph
paper · pdf · doi:10.1038/s41534-019-0191-6
published as npj Quantum Information 5, 76 (2019) · 9 pages, 3 figures, small changes, some material added. For related work see also A. Dahlberg et al (arxiv:1805.05305, arXiv:1805.05306)
openalex created_date 2018/05/17 · arxiv created 2018/07/06 · openalex publication_date 2019/09/06 · arxiv updated 2020/07/14 · openalex updated_date 2026/08/05
Abstract Quantum communication between distant parties is based on suitable instances of shared entanglement. For efficiency reasons, in an anticipated quantum network beyond point-to-point communication, it is preferable that many parties can communicate simultaneously over the underlying infrastructure; however, bottlenecks in the network may cause delays. Sharing of multi-partite entangled states between parties offers a solution, allowing for parallel quantum communication. Specifically for the two-pair problem, the butterfly network provides the first instance of such an advantage in a bottleneck scenario. In this paper, we propose a more general method for establishing EPR pairs in arbitrary networks. The main difference from standard repeater network approaches is that we use a graph state instead of maximally entangled pairs to achieve long-distance simultaneous communication. We demonstrate how graph-theoretic tools, and specifically local complementation, help decrease the number of required measurements compared to usual methods applied in repeater schemes. We examine other examples of network architectures, where deploying local complementation techniques provides an advantage. We finally consider the problem of extracting graph states for quantum communication via local Clifford operations and Pauli measurements, and discuss that while the general problem is known to be NP-complete, interestingly, for specific classes of structured resources, polynomial time algorithms can be identified.