Investigation of Long-Term Stability of Single-Photon Quantum Key Distribution in a Polarization Coding Scheme

Read more Abstract
Experimental results demonstrating long-term stability of the operation of our atmospheric quantum cryptography setup using the BB84 protocol and polarization coding are presented. It was shown that the “sifted” quantum key distribution rate and the quantum bit error rate in the key remained constant for 1 hour and were equal to 10 kbit/s and 6.5 %, respectively, at a distance between the transmitter and the receiver equal to 20 cm. Theoretical dependences of the secret quantum key generation rate on a quantum channel transmission coefficient for single-photon detectors, which were used in this experiment, and for new detectors with a reduced level of dark pulses are given.

Keywords
quantum cryptography, BB84 protocol, polarization coding, single-photon detectors
Funding
This work was supported by A. V. Rzhanov Institute of Semiconductor Physics SB RAS and Novosibirsk State University
УДК 535.14

Investigation of Long-Term Stability  of Single-Photon Quantum Key Distribution  in a Polarization Coding Scheme