Work

Field Demonstration of a Passive Phase and Polarization Stabilization Architecture for Sagnac Twin-Field QKD

Year: 2026

Type: article

Abstract: Twin-field quantum key distribution (TF-QKD) relies on first-order interference between coherent optical fields combined at an intermediate station, which requires simultaneous phase and polarization stabilization. We present a Sagnac-like interferometric architecture arranged in a hybrid star–bus network topology that enables any-to-any connectivity while providing passive stabilization of phase and polarization fluctuations for multiple wavelengths. The proposed configuration, which integrates Faraday mirrors in a Plug-and-Play scheme, operates without active feedback. Experimental results in a 110 km-long installed fiber link between the cities of Linköping and Nyköping, Sweden, show 99.2% visibility maintained over 14 h of continuous operation with 0.33% standard deviation. The main limitation of this configuration—Rayleigh backscattering—was circumvented by time filtering.

Source: IEEE Transactions on Quantum Engineering

DOI: 10.1109/tqe.2026.3728701

Authors: Martin Clason, Christiano M. S. do Nascimento, Felipe Calliari, Joakim Argillander, Guilherme B. Xavier, Guilherme P. Temporão

Institutions: Linköping University, Serviço Nacional de Aprendizagem Industrial, Universidade SENAI CIMATEC, Pontifícia Universidade Católica do Rio de Janeiro

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,075

OpenAlex ID: W7204605677

FWCI:

Cites: 49

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Related to: 10