Erlangen 2018 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 51: Poster: Quantum Optics and Photonics IV
Q 51.39: Poster
Wednesday, March 7, 2018, 16:15–18:15, Redoutensaal
Heralded Entanglement of Single Atoms over Long Distances — •Tim van Leent1, Robert Garthoff1, Kai Redeker1, Wenjamin Rosenfeld1,2, and Harald Weinfurter1,2 — 1Ludwig-Maximilians-Universität, München — 2Max-Planck-Institut für Quantenoptik, Garching
The concept of quantum repeaters paves the way towards a scalable quantum network, which is essential for large scale quantum communication and distributed quantum computing. The basis of a quantum network is entanglement between separated quantum memories. One of the current experimental challenges is to generate entanglement over long distances.
Here we present an experimental setup which entangles two Rb-87 atoms separated by a distance of 400 meters. Starting with atom-photon entanglement in both traps, the entanglement swapping protocol is employed to generate heralded entanglement between the atoms [1]. Together with a fast and efficient atomic state readout scheme a loophole-free violation of Bell's inequality was demonstrated [2], which is the key element in advanced protocols, such as certified generation of random numbers and device-independent quantum key distribution.
The next goal is to increase the distance between the entangled atoms. Milestones along this path are increasing the event rate, converting photons to telecom wavelengths, and improving the coherence time of the atomic state.
[1] J. Hofmann, Science 337, 72 (2012)
[2] W. Rosenfeld, Phys. Rev. Lett. 119, 010402 (2017)