Zusammenfassung
Die Quantenkryptographie ist die erste Anwendung von direkten Quanteneffekten, die heutzutage bereits in diversen Labors zu Produkten weiterentwickelt wird. Der von den Autoren verfolgte Ansatz verwendet quantenmechanische Verschränkung zwischen Photonen. Die deshalb auftretenden, neuartigen Effekte bewirken, dass ein "bedingungslos geheimer Schlüssel" zwischen den Kommunikationspartnern ausgetauscht werden kann. In diesem Artikel wird erstmalig die Verteilung von Polarisationsverschränkung über längere Distanzen in Glasfasern gezeigt. Die auftretenden Korrelationen zeigen solch hohe Güte, wie sie für den Aufbau eines geheimen Schlüssels notwendig ist.
Summary
Quantum cryptography is the first application of a real quantum technology to come on the market. The development is still largely performed in various research laboratories, however, commercialization on a larger scale is expected soon. Our aim is to use entanglement between photons as a quantum resource to form an "unconditional secure key" between communication partners. In this article we present for the first time the distribution of polarization entangled photons over long distances in optical fibers. The correlations are measured with such high quality that they are sufficient to extract a secure key.
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Poppe, A., Hübel, H., Schrenk, B. et al. Der Einsatz verschränkter Photonen für die Quantenkryptographie. Elektrotech. Inftech. 124, 142–148 (2007). https://doi.org/10.1007/s00502-007-0429-4
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DOI: https://doi.org/10.1007/s00502-007-0429-4