Stuttgart 2012 – wissenschaftliches Programm
Q 69.3: Vortrag
Freitag, 16. März 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 . 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  and recent ones that make use of hyper-entanglement .
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