Entanglement of nanophotonic quantum memory nodes in a telecom network

• 成果类型: Article
• 署名作者: Knaut, C. M.; Suleymanzade, A.; Wei, Y. -C.; Assumpcao, D. R.; Stas, P. -J.; Huan, Y. Q.; Machielse, B.; Knall, E. N.; Sutula, M.; Baranes, G.; Sinclair, N.; De-Eknamkul, C.; Levonian, D. S.; Bhaskar, M. K.; Park, H.; Loncar, M.; Lukin, M. D.
• 署名单位: Harvard University; Harvard University; Massachusetts Institute of Technology (MIT); Harvard University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4721
• DOI: 10.1038/s41586-024-07252-z
• 发表日期: 2024-05-16
• 页码: 573-+
• 关键词: heralded entanglement; single atoms

摘要

A key challenge in realizing practical quantum networks for long-distance quantum communication involves robust entanglement between quantum memory nodes connected by fibre optical infrastructure(1-3). Here we demonstrate a two-node quantum network composed of multi-qubit registers based on silicon-vacancy (SiV) centres in nanophotonic diamond cavities integrated with a telecommunication fibre network. Remote entanglement is generated by the cavity-enhanced interactions between the electron spin qubits of the SiVs and optical photons. Serial, heralded spin-photon entangling gate operations with time-bin qubits are used for robust entanglement of separated nodes. Long-lived nuclear spin qubits are used to provide second-long entanglement storage and integrated error detection. By integrating efficient bidirectional quantum frequency conversion of photonic communication qubits to telecommunication frequencies (1,350nm), we demonstrate the entanglement of two nuclear spin memories through 40km spools of low-loss fibre and a 35-km long fibre loop deployed in the Boston area urban environment, representing an enabling step towards practical quantum repeaters and large-scale quantum networks.