Stuttgart 2012 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

Q: Fachverband Quantenoptik und Photonik

Q 69: Quanteninformation: Kommunikation

Q 69.3: Talk

Friday, March 16, 2012, 14:30–14:45, V38.04

Quantum repeaters and quantum key distribution: the influence of distillation on the secret key rate — •Sylvia Bratzik, Hermann Kampermann, and Dagmar Bruß — Heinrich-Heine-Universität, Institut für theoretische Physik III, Universitätsstr. 1, 40225 Düsseldorf

The resource for entanglement-based quantum key distribution (QKD) are photon pairs which are distributed over the desired distance. As the probability that a photon is absorbed by the fiber degrades exponentially, recent QKD setups are limited to around two hundred kilometers. This distance can be overcome using a quantum repeater [1]. The quantum repeater stations which are situated at the intermediate positions perform entanglement swapping and entanglement distillation. Without entanglement distillation, the fidelity of the final quantum state may drop to a level such that it cannot be used for quantum key distribution. We investigate under which circumstances entanglement distillation is necessary for long-distance quantum key distribution. For this purpose we study distillation protocols with dual-rail entanglement [2] and recent ones that make use of hyper-entanglement [3].
H.J. Briegel, W. Dür, J. I. Cirac, and P. Zoller, Phys. Rev. Lett. 81, 5932 (1998).
C.H. Bennett et al., Phys. Rev. Lett. 76, 722 (1996); D. Deutsch et al., Phys. Rev. Lett. 77, 2818 (1996).
C. Wang, H. Q. Ma, R. Z. Jiao, and Y. Zhang, Eur. Phys. J. D 64, 573 (2011); Y.-B. Sheng and F.-G. Deng, Phys. Rev. A 81, 032307 (2010).