Quantum Networking at the Speed of Quantum Computation: Kilohertz Entanglement in a Heterogeneous Quantum System

Authors:Lukas Hartung, Pierre Barral, Noah Glachman, George Toh, Jacob H. Davidson, Sagnik Saha, Alexander Chuang, Matthew C. Cambria, Madison Sutula, Alexander Abulnaga, Julia Breevord, John Chiaverini, Ian Counts, Aos Dabbagh, Christian Dangel, Skylar Deckoff-Jones, Chawina De-Eknamkul, Jonathan Dietz, Riley Forst, Prithvi Gundlapalli, Jeonghoon Ha, Michael Haas, Ezekiel Meulbroek, Andrea Mucchietto, Daniel Riedel, Jonah Sachs, Jeremy Sage, Mikhail Shalaev, Harriet Shi, Denis Sukachev, Yichao Yu, Johannes Borregaard, Christopher Monroe, Nicholas Mondrik, Mihir Bhaskar, Bart Machielse, Matteo Pompili, Carsten Robens, David Levonian

Abstract:Distributed quantum computing requires rapid, high-fidelity entanglement between qubits in separate processor modules. Photonic links between single-atom qubits provide switchable, long-range connections, but photon loss limits their entanglement rate. Here we entangle a trapped $^{138}$Ba$^{+}$ ion with a silicon-vacancy (SiV$^{-}$) center in a diamond nanophotonic cavity. A photon emitted by the ion is converted in wavelength and encoding, reflected from the SiV$^{-}$--cavity system and detected, so that a single detected photon heralds entanglement. Including all conversion losses, we generate ion--SiV$^{-}$ Bell pairs at an average rate of 1.03(1)\,kHz with a fidelity of 87.9(7)\%. This is four times the rate of the fastest photonic link between two trapped ions and corresponds to one Bell pair per millisecond, matching the cycle time of planned trapped-ion processors.

arXiv:2610.10705 [quant-ph]

(or arXiv:2610.10705v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2610.10705 arXiv-issued DOI via DataCite (pending registration)