Trapped atomic ions embedded in optical cavities are a promising platform to enable long-distance quantum networks and their most far-reaching applications. Here we achieve and analyze photon indistinguishability in a telecom-converted ion-cavity system. First, two-photon interference of cavity photons at their ion-resonant wavelength is observed and found to reach the limits set by spontaneous emission. Second, this limit is shown to be preserved after a two-step frequency conversion replicating a distributed scenario, in which the cavity photons are converted to the telecom C band and then back to the original wavelength. The achieved interference visibility and photon efficiency would allow for the distribution and practical verification of entanglement between ion-qubit registers separated by several tens of kilometers.
@article{arxiv.1912.09259,
title = {Indistinguishable photons from a trapped-ion quantum network node},
author = {M. Meraner and A. Mazloom and V. Krutyanskiy and V. Krcmarsky and J. Schupp and D. Fioretto and P. Sekatski and T. E. Northup and N. Sangouard and B. P. Lanyon},
journal= {arXiv preprint arXiv:1912.09259},
year = {2020}
}
Comments
Main text: 4 pages with 3 figures. Supplementary material: 11 pages with 5 figure