INVESTIGATION OF LONG-TERM STABILITY OF THE FREE-SPACE QUANTUM KEY DISTRIBUTION AT A DISTANCE OF 20 M IN A POLARIZATION CODING SCHEME
A. S. Pleshkov, A. V. Kolyako, D. B. Tretyakov, I. I. Ryabtsev, I. G. Neizvestny
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: quantum communication, BB84 protocol, photon polarization coding, single-photon detectors
Abstract
The operation of our atmospheric quantum cryptography setup using the BB84 protocol and polarization coding has been investigated experimentally. The "sifted" quantum key distribution rate and the quantum bit error rate in the key remain constant for 1 hour and are equal to 7558±83 bit/s and 5.1±0.84%, respectively, at a distance of 20 m between the transmitter and receiver. The minimum possible transmittance of a quantum channel is calculated for these parameters of our setup.
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