Noise-immunity Kazan quantum line at 143 km regular fiber link

We experimentally demonstrate a long-distance quantum communication at 143 km between the city of Kazan and the urban-type village of Apastovo in the Republic of Tatarstan by using quantum key distribution prototype providing high noise-immunity of network lines and nodes due to phase coding in subcarrier wave. Average secret key generation rate was 12 bits per second with losses in the line of 37 decibels for a distance of 143 km during 16.5 hours of continuous field test. The commercialization perspectives of the demonstrated long-range QKD system are discussed.