Year: 2025
Type: article
Abstract: The practical deployment of Continuous Variables Quantum Key Distribution (CV-QKD) systems benefits from existing optical fiber telecommunication infrastructures. However, optical fibers introduce random variations in the state of polarization, which degrades the system's performance.We consider a CV-QKD system featuring a polarization diversity heterodyne receiver and the constant modulus algorithm (CMA) to compensate for the polarization drifts in the quantum channel. Our setup can effectively realign Alice's quantum signal with Bob's local oscillator for polarization drift variances below \(10^{-10}\) .This value is compatible with most experimental implementations, allowing for accurate estimation of the channel transmission and excess noise parameters. This validates the approximation of real-world implementations under polarization drift to an ideal scenario without polarization drift, ensuring that the security proof remains applicable for polarization drift variances below $ 10^{-10} $.Our results establish operational limits for passive polarization drift compensation using a polarization diversity receiver combined with digital CMA.This enables long-term stability in \linebreak CV-QKD systems, eliminating the need for active polarization controllers and manual adjustments.
Source: EPJ Quantum Technology
Institution: University of Aveiro
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,190
Awards: G1167214205, G1578237752, Quantum Enabled Secure Multiparty Computation for Genomic Medicine, G2144570049, G2415629801, Instituto de Telecomunicações, G3850789590, G3891694003, G4730158122, G491858407, Real Time Implementation of a Continuous Variable Quantum Key Distribution System, G59476441, G6251103608, G6329845220, G7075478681, Quantum-Enabled Privacy and Security Services to Support Next Generation Network Infrastructures
OpenAlex ID: W4415208329