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Q: Fachverband Quantenoptik und Photonik
Q 23: Poster 2: Intersectional Session
Q 23.21: Poster
Tuesday, March 15, 2011, 18:00–21:00, P1
Improving entanglement based quantum key distribution through turbulent atmosphere — •Bettina Heim1,2,3, Chris Erven3, Raymond Laflamme3,4, Gregor Weihs3,5, and Thomas Jennewein3 — 1Max Planck Institute for the Science of Light, Erlangen, Germany — 2Institute of Optics, Information und Photonics, University of Erlangen-Nuremberg, Erlangen, Germany — 3Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada — 4Perimeter Institute, Waterloo, Canada — 5Institute for Experimental Physics, University of Innsbruck, Innsbruck, Austria
Within the framework of our free-space quantum key distribution system, we study influences of the turbulent atmosphere on entangled photons sent over a 1.3 km free-space link, and explore the possibility of optimizing the quantum transmisson in this situation. Entangled photons are created in a Sagnac configuration [1], using a periodically poled KTP non-linear optical crystal that is placed in an interferometer loop and pumped bi-directionally. One photon of each pair is detected locally, the other one is sent through the free-space channel. We specifically studied the effects of the atmospheric channel on the entanglement properties and the performance of our system under various losses and pump rates with a view to improving the signal-to-noise ratio of the system in order to increase the secret key rate. In the future, we intend to perform the same study with two independent free-space links. [2].
[1] C. Erven et al., QuantumCom2009, LNICST 36, 108-116, 2010.
[2] C. Erven et al., Opt. Exp. 16, 16840-16853 (2008).