Entanglement of Trapped-Ion Qubits Separated by 230 Meters

2023/02/02 by V. Krutyanskiy, Maria Galli, Vojtech Krcmarsky +13 · 1 voice · 6 citations
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum optics and atomic interactions

paper · doi:10.1103/physrevlett.130.050803

openalex publication_date 2023/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31

Abstract

We report on an elementary quantum network of two atomic ions separated by 230 m. The ions are trapped in different buildings and connected with 520(2) m of optical fiber. At each network node, the electronic state of an ion is entangled with the polarization state of a single cavity photon; subsequent to interference of the photons at a beam splitter, photon detection heralds entanglement between the two ions. Fidelities of up to (88.0+2.2-4.7)% are achieved with respect to a maximally entangled Bell state, with a success probability of 4×10^-5. We analyze the routes to improve these metrics, paving the way for long-distance networks of entangled quantum processors.

Citations

• Quantum repeaters based on single trapped ions
• Advances in quantum cryptography

Cited by

• A Metropolitan-scale Multiplexed Quantum Repeater with Bell Nonlocality
• Reinforcement Learning for Quantum Network Control with Application-Driven Objectives
• Frequency drift corrected ultra-stable laser through phase-coherent fiber producing a quantum channel
• A Framework for Quantum Data Center Emulation Using Digital Quantum Computers
• Remote Quantum Networks based on Quantum Memories
• Retroreflective surface optimisation for optical cavities with custom mirror profiles

Discussions

• We confirm this by testing purpose-designed GME witnesses based on fidelities to 8 different GHZ-type states. In the future, the photons can be mapped onto remote matter-based qubits, e.g., as in do [bsky, 1 points, 1 comments]

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