Distribution of GHz Sequential Time-Bin Entanglement in a Metropolitan Fiber Network

Author(s): Martin Achleitner, Alessandro Trenti, Philip Walther, Hannes Huebel
Abstract: Efficient generation and high-quality distribution of entanglement is becoming increasingly more relevant in the field of quantum technologies, with important applications such as multiparty computation as well as quantum key distribution (QKD) on the rise. Quantum communication protocols based on entanglement offer an inherent quantum based randomness for key generation and provide in general higher security compared to prepare and measure implementations. Moreover, the future quantum internet will also be based on the distribution of entanglement for securely connecting quantum computers in a network. In this work we show the feasibility of using sequential time-bin entangled states for quantum key distribution in metropolitan networks using off-the-shelf components. The time-bin encoding ensures high fidelity distribution robust against random polarisation fluctuations occuring in optical fibers. Modulated laser pulses in the GHz frequency range are used to generate time-bin entangled photon pairs. The entangled photons are then sent over an about 30 km long (9.5 dB loss) fiber link within the Vienna fiber network, showing high degree of distributed entanglement with a measured 93% quantum visibility.
Organisation(s): Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s): Austrian Institute of Technology
Journal: IEEE Journal of Selected Topics in Quantum Electronics
Volume: 31
No. of pages: 8
ISSN: 1077-260X
DOI: https://doi.org/10.1109/JSTQE.2025.3539921
Publication date: 09-2025
Peer reviewed: Yes
Austrian Fields of Science 2012: 103025 Quantum mechanics, 103026 Quantum optics
Keywords
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering
Portal url: https://ucrisportal.univie.ac.at/en/publications/0927a443-02c4-4eae-98d1-14f4c4747be7