Dr. Rupert Ursin IQOQI - Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences

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Dr. Rupert Ursin

IQOQI - Institute for Quantum Optics and Quantum Information,
Austrian Academy of Sciences

Free Space

Quantum entanglement is the main resource to endow the field of quantum information processing with powers that exceed those of classical communication and computation. In view of applications such as quantum cryptography or quantum teleportation, extension of quantum-entanglement-based protocols to global distances is of considerable practical interest. Here we experimentally demonstrate entanglement-based quantum key distribution over 144 km. One photon is measured locally at the Canary Island of La Palma, whereas the other is sent over an optical free-space link to Tenerife, where the Optical Ground Station of the European Space Agency acts as the receiver. This exceeds previous free-space experiments by more than an order of magnitude in distance, and is an essential step towards future satellite-based quantum communication and experimental tests on quantum physics in space.

Various projects on the Canary Islands in a close collaboration with the European Space Agency (ESA) and LMU Munich where sucessfully performed up to now.

Here we report an experiment where we were able to generate a quantum cryptographic key over 144 km by exploiting the randomness and the strong correlations inherent in quantum entanglement. This experiment demonstrates a first important step towards future satellite-based distribution of entangled photons to two different ground stations to establish a worldwide network for quantum communication and fundamental tests of quantum physics. A schematic layout of the experimental set-up on the Canary Islands is shown in Fig. 1. Polarization-entangled photon pairs were generated on Roque de los Muchachos (2,392 m above sea level) on the island of La Palma.

Fig 1: Quantum communication link between the canary isand La Palma and Tenerife

Publication:

Entanglement based quantum communication over 144 km
R. Ursin, F. Tiefenbacher, T. Schmitt-Manderbach, H. Weier, T. Scheidl, M. Lindenthal, B. Blauensteiner, T. Jennewein, J. Perdigues, P. Trojek, B. Ömer, M. Fürst, M. Meyenburg, J. Rarity, Z. Sodnik, C. Barbieri, H. Weinfurter, A. Zeilinger
(quant-ph/0607182)

Experimental Demonstration of Free-Space Decoy-State Quantum Key Distribution over 144 km
T. Schmitt-Manderbach, H, Weier, M. Fürst, R. Ursin, F. Tiefenbacher, Th. Scheidl, J. Perdigues, Z. Sodnik, J. G. Rarity, A. Zeilinger, H. Weinfurter,
Phys. Rev. Lett. 98, 010504 (2007)

Applications of quantum communication protocols in real world scenarios towards space
R. Ursin, F. Tiefenbacher, T. Jennewein and A. Zeilinger
E&I Electronics 5, 149 (2007)

Entanglement based quantum communication over 144 km
R. Ursin, F. Tiefenbacher, T. Schmitt-Manderbach, H. Weier, T. Scheidl, M. Lindenthal, B. Blauensteiner, T. Jennewein, J. Perdigues, P. Trojek, B. Ömer, M. Fürst, M. Meyenburg, J. Rarity, Z. Sodnik, C. Barbieri, H. Weinfurter, A. Zeilinger
Nature Physics 3, 481 - 486 (2007)

Free-space quantum key distribution over 144 km
M. Fürst, H. Weier, T. Schmitt-Manderbach, R. Ursin, F. Tiefenbacher, T. Scheidl, M. Lindenthal, B. Blauensteiner, and T. Jennewein, P. Trojek, J. M. Perdigues and Z. Sodnik, C. Barbieri, J. G. Rarity, A. Zeilinger, H. Weinfurter
Proceedings of SPIE, Volume 63990G (2006)

Quantum Information and quantum physics in Space
R. Ursin, Th. Jennewein, T. Schmitt-Manderbach, H. Weier, J. Perdigues, J. Rarity, C. Barbieri, H. Weinfurter and A. Zeilinger
1st Colloquium on Scientific and Fundamental Aspects of the Galileo Programme, 1- 4 October 2007 - Toulouse, France

Collaboration:

- LMU Munich, Germany

- MPQ Garching, Germany

- University of Bristol, UK

- University of Padova, Italy

- ARC Seibersdorf, Austria

- ESA - ESTEC, The Netherlands

- IAC, Spain

Links:

ESA Project Website (internal only)

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