2024-10-31 オランダ・デルフト工科大学（TUDelft)
＜関連情報＞
- https://www.tudelft.nl/en/2024/tu-delft/a-rudimentary-quantum-network-link-between-dutch-cities
- https://www.science.org/doi/10.1126/sciadv.adp6442
- https://www.nature.com/articles/s41586-022-04697-y
固体量子ビットのエンタングルメントを首都圏規模で予告 Metropolitan-scale heralded entanglement of solid-state qubits
Arian J. Stolk, Kian L. van der Enden, Marie-Christine Slater, Ingmar te Raa-Derckx, […], and Ronald Hanson
Science Advances Published:30 Oct 2024
DOI:https://doi.org/10.1126/sciadv.adp6442
Abstract
A key challenge toward future quantum internet technology is connecting quantum processors at metropolitan scale. Here, we report on heralded entanglement between two independently operated quantum network nodes separated by 10 kilometers. The two nodes hosting diamond spin qubits are linked with a midpoint station via 25 kilometers of deployed optical fiber. We minimize the effects of fiber photon loss by quantum frequency conversion of the qubit-native photons to the telecom L-band and by embedding the link in an extensible phase-stabilized architecture enabling the use of the loss-resilient single-click entangling protocol. By capitalizing on the full heralding capabilities of the network link in combination with real-time feedback logic on the long-lived qubits, we demonstrate the delivery of a predefined entangled state on the nodes irrespective of the heralding detection pattern. Addressing key scaling challenges and being compatible with different qubit systems, our architecture establishes a generic platform for exploring metropolitan-scale quantum networks.
量子ネットワークにおける非隣接ノード間の量子テレポーテーション Qubit teleportation between non-neighbouring nodes in a quantum network
S. L. N. Hermans,M. Pompili,H. K. C. Beukers,S. Baier,J. Borregaard & R. Hanson
Nature Published:25 May 2022
DOI:https://doi.org/10.1038/s41586-022-04697-y
Abstract
Future quantum internet applications will derive their power from the ability to share quantum information across the network1,2. Quantum teleportation allows for the reliable transfer of quantum information between distant nodes, even in the presence of highly lossy network connections3. Although many experimental demonstrations have been performed on different quantum network platforms4,5,6,7,8,9,10, moving beyond directly connected nodes has, so far, been hindered by the demanding requirements on the pre-shared remote entanglement, joint qubit readout and coherence times. Here we realize quantum teleportation between remote, non-neighbouring nodes in a quantum network. The network uses three optically connected nodes based on solid-state spin qubits. The teleporter is prepared by establishing remote entanglement on the two links, followed by entanglement swapping on the middle node and storage in a memory qubit. We demonstrate that, once successful preparation of the teleporter is heralded, arbitrary qubit states can be teleported with fidelity above the classical bound, even with unit efficiency. These results are enabled by key innovations in the qubit readout procedure, active memory qubit protection during entanglement generation and tailored heralding that reduces remote entanglement infidelities. Our work demonstrates a prime building block for future quantum networks and opens the door to exploring teleportation-based multi-node protocols and applications2,11,12,13.
