Seminário de Computação e Informação Quântica 

16/07/2019, 15:00 — 16:00 — Sala P1, Pavilhão de Matemática
Ben Lanyon, IQOQI and University of Innsbruck

Light-matter entanglement over 50km of optical fibre

When shared between remote locations, entanglement opens up fundamentally new capabilities for science and technology. Envisioned quantum networks use light to distribute entanglement between their remote matter-based quantum nodes. In this short talk, I will present our observation of entanglement between matter (a trapped ion) and light (a photon) over 50 km of optical fibre [1]: two orders of magnitude further than the state of the art and a practical distance to start building large-scale quantum networks. Our methods include an efficient source of ion-photon entanglement via cavity-QED techniques (0.5 probability on-demand fibre-coupled photon from the ion) and a single photon quantum frequency converter to the 1550 nm telecom C band (0.25 fibre-coupled device efficiency). Modestly optimising and duplicating our system could allow for 100 km-spaced ion-ion entanglement at rates over 1 Hz. Our results therefore show a path to entangling remote registers of quantum-logic capable trapped-ion qubits, and the optical atomic clock transitions that they contain, spaced by hundreds of kilometres.

1. Krutyanskiy, M. Meraner, J. Schupp, V. Krcmarsky, H. Hainzer, B. P. Lanyon. Light-matter entanglement over 50 km of optical fiber, arXiv:1901.06317.