Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 3: Poster Quanteninformation, -kommunikation und Quantencomputer
Q 3.22: Poster
Freitag, 4. März 2005, 11:00–12:30, Poster HU
Long-Distance Free-Space Distribution of Quantum Entanglement over Vienna — •Michael Lindenthal1, Kevin Resch1, Bibiane Blauensteiner1, Hannes Böhm1, Alessandro Fedrizzi1, Andreas Poppe1, Tobias Schmitt-Manderbach2, Michael Taraba1, Rupert Ursin1, Philip Walther1, Henning Weier2, Harald Weinfurter2,3, and Anton Zeilinger1,4 — 1Institut für Experimentalphysik, Universität Wien, Boltzmanngasse 5, A-1090 Wien, Austria — 2Sektion Physik, Ludwig-Maximilians-Universität, D-80797 München, Germany — 3Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany — 4Institut für Quantenoptik und Quanteninformation, Österreichisch Akademie der Wissenschaften, Boltzmanngasse 3, A-1090 Wien, Austria
We have established a real-world free-space quantum channel over 7.8 km and demonstrate the distribution of entangled photons. The transmitter is placed at an observatory and the receiver on the 46th floor of an office skyscraper in Vienna, Austria. Using locally-recorded time stamps and a public internet channel, coincident counts from correlated photons are demonstrated to violate a Bell inequality by over ten standard deviations. This confirms the high quality of the shared entanglement. In this experiment the horizontal free-space distance is chosen, so that the attenuation the light undergoes corresponds approximately to the attenuation from space to earth. This work is an encouraging step towards satellite-based distribution of quantum entanglement and future intra-city quantum networks.