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Full polarization random drift compensation method for quantum communication

Ramos, M. F. ; Silva, N. A. ; Muga, N. J. ; Pinto, A. N.

Optics Express Vol. 30, Nº 5, pp. 6907 - 6920, February, 2022.

ISSN (print): 1094-4087
ISSN (online):

Scimago Journal Ranking: 1,39 (in 2020)

Digital Object Identifier: 10.1364/OE.445228

Long-term quantum key distribution (QKD) using polarization encoding requires a random drift compensation method. We propose a method to compensate any state of polarization based on the quantum bit error rate (QBER) of two states from two non-orthogonal mutually unbiased bases. The proposed method does not require dedicated equipment, and through a simple but highly efficient feedback loop it compensates the polarization random drift suffered by photons while transmitted over the optical fiber quantum channel. A QBER lower than 2% was observed even considering imperfect single photon detectors. Besides, we verify a 82% secret key rate generation improvement in a finite-key size BB84 implementation for a 40 km fiber-optics quantum channel.