We entangle each individual matter-qubit in a register of ten to a separate travelling photon. The qubits are encoded in a string of cotrapped atomic ions. By switching the trap confinement, ions are brought one at a time into the waist of an optical cavity and emit a photon via a laser-driven cavity-mediated Raman transition. The result is a train of photonic-qubits, each near-maximally entangled by their polarisation with a different ion-qubit in the string. An average ion-photon Bell state fidelity of 92(1)% is achieved, for an average probability for detecting each single photon of 9.1(8)%. The technique is directly scalable to larger ion-qubit registers and opens up the near-term possibility of entangling distributed networks of trapped-ion quantum processors, sensing arrays and clocks.
@article{arxiv.2406.09480,
title = {A photon-interfaced ten qubit quantum network node},
author = {M. Canteri and Z. X. Koong and J. Bate and A. Winkler and V. Krutyanskiy and B. P. Lanyon},
journal= {arXiv preprint arXiv:2406.09480},
year = {2024}
}