Distributing entanglement and single photons through an intra-city, free-space quantum channel
- Author(s)
- Kevin Resch, Michael Lindenthal, Bibiane Blauensteiner, Hannes Böhm, Alessandro Fedrizzi, Christian Kurtsiefer, Andreas Poppe, Tobias Schmitt-Manderbach, Michael Taraba, Rupert Ursin, Philip Walther, Henning Weier, Harald Weinfurter, Anton Zeilinger
- Abstract
We have distributed entangled photons directly through the atmosphere to a receiver station 7.8 km away over the city of Vienna, Austria at night. Detection of one photon from our entangled pairs constitutes a triggered single photon source from the sender. With no direct time-stable connection, the two stations found coincidence counts in the detection events by calculating the cross-correlation of locally-recorded time stamps shared over a public internet channel. For this experiment, our quantum channel was maintained for a total of 40 minutes during which time a coincidence lock found approximately 60000 coincident detection events. The polarization correlations in those events yielded a Bell parameter, S=2.27±0.019, which violates the CHSH-Bell inequality by 14 standard deviations. This result is promising for entanglement-based free-space quantum communication in high-density urban areas. It is also encouraging for optical quantum communication between ground stations and satellites since the length of our free-space link exceeds the atmospheric equivalent. © 2005 Optical Society of America
- Organisation(s)
- External organisation(s)
- National University of Singapore (NUS), Ludwig-Maximilians-Universität München, Österreichische Akademie der Wissenschaften (ÖAW)
- Journal
- Optics Express
- Volume
- 13
- Pages
- 202-209
- No. of pages
- 8
- DOI
- https://doi.org/10.1364/OPEX.13.000202
- Publication date
- 01-2005
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103026 Quantum optics
- Keywords
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/distributing-entanglement-and-single-photons-through-an-intracity-freespace-quantum-channel(8e738c0f-0acf-49de-89bf-ec7d7dda7245).html