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Overview of free-space continuous-variable quantum key distribution technology
D.A. Kargina1, R.K. Goncharov1,2, M.V. Dashkov3

1ITMO University, Quantum Communications Laboratory, 197101, Saint Petersburg, Russia, Kadetskaya line 3;
2SMARТС-Quantelecom LLC, 199178, Saint Petersburg, Russia, 6th line V.O. 59, bld. 1, lit. B, room 17/6N;
3Volga Region State University of Telecommunications and Informatics (PSUTI), 443090, Samara, Russia, Moskovskoye Shosse 77

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DOI: 10.18287/COJ1684

Article ID: 1684

Language: English

Abstract:
Free-space quantum key distribution opens up new possibilities for the development of quantum communication systems, facilitating the deployment of quantum networks in physically hard-to-reach areas and across wide landscapes without the use of optical fibers. This approach overcomes restrictions associated with cable laying and provides a more flexible infrastructure for quantum information transmission. Together with the use of continuous-variable protocols, it becomes possible to organize secure information transfer using optimal scalable communication systems despite deleterious environmental influences. This paper reviews key achievements and technical aspects of implementing continuous-variable quantum key distribution in atmospheric channels, considering the main atmospheric effects such as turbulence, scattering, and beam wandering. We present the current state of continuous-variable quantum key distribution systems in free space and their practical implementations, including successful experimental projects and prototypes. Prospects for further development, including integration with existing telecommunications networks and potential application areas, are discussed.

Keywords:
quantum key distribution, atmospheric quantum channels, turbulence, continuous variables.

Acknowledgements:
This research was supported by the Russian Science Foundation (project 24-29-00786).

Citation:
Kargina DA, Goncharov RK, Dashkov MV. Overview of free-space continuous-variable quantum key distribution technology. Computer Optics 2026; 50(1): 1684. DOI: 10.18287/COJ1684.

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