Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IET conference proceedings.

Demonstration of GHz sequential time-bin entanglement distribution in a metropolitan fiber network

Alessandro Trenti, Martin Achleitner, Philip John Walther, Hannes Hübel

Published Nov 13, 2023• 0 citations
Publisher

Abstract

Entanglement is arguably one of the most important resources in the field of quantum information, with key applications in quantum communication and computing. Here, we report on the distribution of GHz sequential time-bin entanglement in a 30km fiber link by using off-the-shelf components.
DOI
10.1049/icp.2023.2372

Related papers

Distribution of GHz sequential Time-bin Entanglement in a Metropolitan Fiber Network

Martin Achleitner, Alessandro Trenti, Philip Walther +1 more

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 30km long (9.5dB loss) fiber link within the Vienna fiber network, showing high degree of distributed entanglement with a measured 93\% quantum visibility.

quant-pharXiv:2605.13359•IEEE Journal of Selected Topics in Quantum Electronics•May 14, 2026•2 citations

Field test of entanglement swapping over 100-km optical fiber with independent 1-GHz-clock sequential time-bin entangled photon-pair sources

Qi-Chao Sun, Yang-Fan Jiang, Ya-li Mao +12 more

Realizing long distance entanglement swapping with independent sources in the real-world condition is important for both future quantum network and fundamental study of quantum theory. Currently, demonstration over a few of tens kilometer underground optical fiber has been achieved. However, future applications demand entanglement swapping over longer distance with more complicated environment. We exploit two independent 1-GHz-clock sequential time-bin entangled photon-pair sources, develop several automatic stability controls, and successfully implement a field test of entanglement swapping over more than 100-km optical fiber link including coiled, underground and suspended optical fibers. Our result verifies the feasibility of such technologies for long distance quantum network and for many interesting quantum information experiments.

arXiv:1704.03960•Apr 13, 2017•0 citations

Multi-dimensional frequency-bin entanglement-based quantum key distribution network

George Claudiu Crisan, Antoine Henry, Dario Fioretto +7 more

Abstract Quantum networks enhance quantum communication schemes and link multiple users over large areas. Harnessing high dimensional quantum states - qu-d-its - allows for a denser transfer of information with increased robustness to noise compared to qubits. Frequency encoded qu-d-its can be manipulated at telecom wavelengths with off-the-shelf fibered devices. We use a low free spectral range silicon microresonator to propose, assess and optimize a reconfigurable entanglement-based quantum key distribution network with frequency-bin encoded Bell states of dimension d = 2 and d = 3, using a single fibered hardware. We achieve secure key rates of 1374 bit/s with qutrits ( d = 3), and estimate the communication range to 295 km with qubits ( d = 2) across 21 parallel two-user quantum channels. This multi-dimensional versatile demonstration is stable beyond 21 h and lays the groundwork for larger dimensionality implementations deployed on metropolitan fiber links.

arXiv:2507.00972•npj Quantum Information•Apr 29, 2026•1 citation

Entanglement swapping over 100 km optical fiber with independent entangled photon-pair sources

Qi-Chao Sun, Yang-Fan Jiang, Ya-Li Mao +12 more

Realizing long-distance entanglement swapping with independent sources in the real-world condition is important for both future quantum networks and fundamental study of quantum theory. Currently, entanglement swapping over a few tens of kilometers of underground optical fiber has been achieved. However, future applications demand entanglement swapping over longer distances in more complicated environments. We exploit two independent 1-GHz-clock sequential time-bin entangled photon-pair sources; develop several automatic stability controls; and successfully implement a field test of entanglement swapping over an optical fiber link of more than 100 km, including coiled, underground, and suspended optical fibers. Our result verifies the feasibility of such technologies for long-distance quantum networks and for many interesting quantum information experiments.

Optica•Oct 2, 2017•86 citations

Quantum communication with time-bin entanglement over a wavelength-multiplexed fiber network

Jin-Hun Kim, Jin-Woo Chae, Youn-Chang Jeong +1 more

In a quantum network involving multiple communicating parties, an important goal is to establish high-quality pairwise entanglement among the users without introducing multiple entangled-photon sources which would necessarily complicate the overall network setup. Moreover, it is preferable that the pairwise entanglement of photons is in the time-bin degree of freedom as the photonic time-bin qubit is ideally suited for fiber-optic distribution. Here, we report an experimental demonstration of a field-deployable quantum communication network involving multiple users, all of whom share pairwise entanglement in the time-bin degree of freedom of photons. In particular, by utilizing a single spontaneous-parametric down-conversion source which produces a broadband pair of photons and the wavelength-division demultiplexing/multiplexing technology, all the communicating parties within the network are always simultaneously ready for quantum communication. To further demonstrate the practical feasibility of a quantum network with time-bin entanglement over a wavelength-multiplexed fiber network, we demonstrate entangled-photon quantum key distribution with three users, each separated by 60 km of optical fibers.

APL Photonics•Dec 31, 2021•54 citations

Demonstration of 75 km-fiber quantum clock synchronization in quantum entanglement distribution network

Bang-Ying Tang, Ming Tian, Huan Chen +7 more

Abstract The quantum entanglement distribution network, serviced as the communication infrastructure which distributes quantum information among remote users, enables many applications beyond the reach of classical networks. Recently, the applications such as quantum key distribution and quantum secure direct communication, have been successfully demonstrated in the quantum entanglement distribution network. In this article, we propose a multi-user round-trip quantum clock synchronization (QCS) scheme in the quantum network, which can be implemented with one single entangled photon source located at the server. The server distributes the entangled photons to remote multiple users with the wavelength division multiplexing strategy, and each user feeds partial received photons back to the server. The clock difference between the server and each user is calculated from the one-way and round-trip propagation times, which are determined according to the time correlation of entangled photons. Afterwards, the demonstration has been conducted between the server and a user over a 75-km-long fiber link, where the measured clock difference uncertainty is 4.45 ps, and the time deviation is 426 fs with an average time of 4000 s. Furthermore, the proposed QCS scheme is linearly scalable to many users, with respect to user hardware and number of deployed fibers.

EPJ Quantum Technology•Nov 22, 2023•18 citations
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 30km long (9.5dB loss) fiber link within the Vienna fiber network, showing high degree of distributed entanglement with a measured 93\% quantum visibility.
Realizing long distance entanglement swapping with independent sources in the real-world condition is important for both future quantum network and fundamental study of quantum theory. Currently, demonstration over a few of tens kilometer underground optical fiber has been achieved. However, future applications demand entanglement swapping over longer distance with more complicated environment. We exploit two independent 1-GHz-clock sequential time-bin entangled photon-pair sources, develop several automatic stability controls, and successfully implement a field test of entanglement swapping over more than 100-km optical fiber link including coiled, underground and suspended optical fibers. Our result verifies the feasibility of such technologies for long distance quantum network and for many interesting quantum information experiments.
Abstract Quantum networks enhance quantum communication schemes and link multiple users over large areas. Harnessing high dimensional quantum states - qu-d-its - allows for a denser transfer of information with increased robustness to noise compared to qubits. Frequency encoded qu-d-its can be manipulated at telecom wavelengths with off-the-shelf fibered devices. We use a low free spectral range silicon microresonator to propose, assess and optimize a reconfigurable entanglement-based quantum key distribution network with frequency-bin encoded Bell states of dimension d = 2 and d = 3, using a single fibered hardware. We achieve secure key rates of 1374 bit/s with qutrits ( d = 3), and estimate the communication range to 295 km with qubits ( d = 2) across 21 parallel two-user quantum channels. This multi-dimensional versatile demonstration is stable beyond 21 h and lays the groundwork for larger dimensionality implementations deployed on metropolitan fiber links.
Realizing long-distance entanglement swapping with independent sources in the real-world condition is important for both future quantum networks and fundamental study of quantum theory. Currently, entanglement swapping over a few tens of kilometers of underground optical fiber has been achieved. However, future applications demand entanglement swapping over longer distances in more complicated environments. We exploit two independent 1-GHz-clock sequential time-bin entangled photon-pair sources; develop several automatic stability controls; and successfully implement a field test of entanglement swapping over an optical fiber link of more than 100 km, including coiled, underground, and suspended optical fibers. Our result verifies the feasibility of such technologies for long-distance quantum networks and for many interesting quantum information experiments.
In a quantum network involving multiple communicating parties, an important goal is to establish high-quality pairwise entanglement among the users without introducing multiple entangled-photon sources which would necessarily complicate the overall network setup. Moreover, it is preferable that the pairwise entanglement of photons is in the time-bin degree of freedom as the photonic time-bin qubit is ideally suited for fiber-optic distribution. Here, we report an experimental demonstration of a field-deployable quantum communication network involving multiple users, all of whom share pairwise entanglement in the time-bin degree of freedom of photons. In particular, by utilizing a single spontaneous-parametric down-conversion source which produces a broadband pair of photons and the wavelength-division demultiplexing/multiplexing technology, all the communicating parties within the network are always simultaneously ready for quantum communication. To further demonstrate the practical feasibility of a quantum network with time-bin entanglement over a wavelength-multiplexed fiber network, we demonstrate entangled-photon quantum key distribution with three users, each separated by 60 km of optical fibers.
Abstract The quantum entanglement distribution network, serviced as the communication infrastructure which distributes quantum information among remote users, enables many applications beyond the reach of classical networks. Recently, the applications such as quantum key distribution and quantum secure direct communication, have been successfully demonstrated in the quantum entanglement distribution network. In this article, we propose a multi-user round-trip quantum clock synchronization (QCS) scheme in the quantum network, which can be implemented with one single entangled photon source located at the server. The server distributes the entangled photons to remote multiple users with the wavelength division multiplexing strategy, and each user feeds partial received photons back to the server. The clock difference between the server and each user is calculated from the one-way and round-trip propagation times, which are determined according to the time correlation of entangled photons. Afterwards, the demonstration has been conducted between the server and a user over a 75-km-long fiber link, where the measured clock difference uncertainty is 4.45 ps, and the time deviation is 426 fs with an average time of 4000 s. Furthermore, the proposed QCS scheme is linearly scalable to many users, with respect to user hardware and number of deployed fibers.