© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

The QTF Backbone: proposal for a nationwide optical fibre backbone in germany for quantum technology and time and frequency metrology

Tara Cubel Liebisch, Peter Kaufmann, H. Schnatz, Susanne Naegele-Jackson, Jochen Kronjäger, Klaus Blaum, S. Kück, Dieter Meschede, Stephan Schiller, Laura Agazzi, S. Alighanbari, Joachim Ankerhold, G. V. Astakhov, Stefanie Barz, Ingo Baumann, Rainer Baumgart, Christoph Becher, Hendrik Bekker, Oliver J. Benson, Paolo Bianco, Ronald Bieber, Immanuel Bloch, Ulrike Blumröder, Rainer Bockholt, Johannes Bouman, Claus Braxmaier, Enrico Brehm, Dagmar Bruß, Dmitry Budker, Hans‐Joachim Bungartz, Erik Busley, J. R. Crespo López-Urrutia, Cornelia Denz, Christian Deppe, Guido Dietl, Fei Ding, Thomas Eickermann, Florian Elsen, Wolfgang Ertmer, Stefan Filipp, Marc Fischer, Jakob Flury, Thomas Fröhlich, Johann Furthner, Ilia Gerhardt, Kay-Uwe Giering, Christoph Glingener, Helmut Grießer, Rüdiger Grimm, Grimm, Christian, Andreas Gritsch, Hack, Fritz, Theodor W. Hänsch, Thomas Halfmann, Andreas Hanemann, Daniel F. Harlacher, Hegemann, Niklas, Tobias Heindel, Robert Heinkelmann, Luis Hellmich, Thomas Hildmann, David Hock, Sven Höfling, Bruno Höft, Hofmann, Harald, Peter Holleczek, R. Holzwarth, Wolfgang Hommel, Thomas Hühn, Urs Hugentobler, David Hunger, Nils Huntemann, Ç. İşsever, Fedor Jelezko, Klaus D. Jöns, Tim Johann, Philippe Jousset, Bernd Jungbluth, Franz X. Käertner, Jonas Kankel, Heike Kaufmann, Dmitry Khabi, Thomas Kissinger, Carsten Klempt, Thomas Klügel, Ann‐Kathrin Kniggendorf, Jan Kodet, U. Konrad, Joachim Kopp, M. Krämer, Stefan Kremling, Michael Krist, Markus Krutzik, Sascha Kwasniok, Yvonne Leifels, Gerd Leuchs, Christian Lisdat, Yuri Litvinov, Manfred Lochter, Peter van Loock

Published Jul 17, 2026• 0 citations

DOI: 10.5445/ir/1000195409

Related papers

The QTF Backbone: proposal for a nationwide optical fibre backbone in Germany for quantum technology and time and frequency metrology

Tara Cubel Liebisch, Peter Kaufmann, H. Schnatz +97 more

The European Physical Journal Special Topics•Jan 1, 2026•0 citations

The QTF Backbone: proposal for a nationwide optical fibre backbone in Germany for quantum technology and time and frequency metrology

Tara Cubel Liebisch, Peter Kaufmann, H. Schnatz +97 more

Abstract The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined to isolated testbeds, with quantum and T&F signals accessible, for example in Germany, to only a few institutions. In this white paper we propose the QTF Backbone: a dedicated national fibre-optic infrastructure in Germany for the networked distribution of Q uantum and T&F signals using dark fibres and specialised hardware. The QTF Backbone is planned as a four-phase deployment over ten years to ensure scalable, sustainable access for research institutions and industry. The concept builds on successful demonstrations of time and frequency distribution at high Technology Readiness Levels (TRLs) across Europe, including PTB–MPQ links in Germany, REFIMEVE in France, and the Italian LIFT network. The QTF Backbone will enable transformative Research and Development (R&D), support a nationwide QTF ecosystem, and ensure the transition from innovation to deployment. As a national and European hub, it will position Germany and Europe at the forefront of quantum networking, as well as T&F transfer.

arXiv:2506.03998•The European Physical Journal Special Topics•Jul 16, 2026•0 citations

European Metrology Network for Quantum Technologies: Roadmaps & Strategic Research Agenda

Ivo Pietro Degiovanni, Marco Gramegna, S. Bize +2 more

•Mar 24, 2021•0 citations

Unrepeated White Rabbit Time Synchronisation over a 300 km Optical Fibre Link

Ben Amies-King, Marco Lucamarini

White Rabbit (WR) technology provides a commercially-available off-the-shelf solution for time synchronisation with sub-nanosecond accuracy and picosecond-level precision over optical fibre links typically spanning tens of kilometres. Such high-performance time dissemination can support a variety of applications, including position, navigation and timing (PNT), financial transactions, metrology, as well as entanglement and quantum key distribution (QKD). Demonstrations of WR over significantly longer distances remain few and far between, particularly in scenarios where intermediate amplification is unavailable, such as stretches of long-haul underwater fibre. In this work, we report the longest unrepeated deployment of WR to date, achieving time synchronisation over a 300 km (51.34 dB) single-span optical fibre link, even in highly asymmetrical configurations, with 99.86% uptime, whilst maintaining picosecond-level precision and sub-nanosecond accuracy. This was achieved through careful selection and optimisation of the components deployed at the link's end points. By leveraging standard telecom fibre and off-the-shelf hardware, our results pave the way for a scalable and standardised timing backbone for large-scale quantum networks, offering a practical route toward time distribution in future heterogeneous quantum communication systems.

quant-pharXiv:2511.23254•Journal of Lightwave Technology•Dec 1, 2025•1 citation

Proposal for a nationwide optical fibre backbone in Germany for quantum technology and time and frequency metrology

T. Cubel, Peter Kaufmann, H. Schnatz +97 more

The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined to isolated testbeds, with quantum and T&F signals accessible, for example in Germany, to only a few institutions. In this white paper we propose the QTF Backbone: a dedicated national fibre-optic infrastructure in Germany for the networked distribution of Quantum and T&F signals using dark fibres and specialised hardware. The QTF Backbone is planned as a four-phase deployment over ten years to ensure scalable, sustainable access for research institutions and industry. The concept builds on successful demonstrations of time and frequency distribution at high Technology Readiness Levels (TRLs) across Europe, including PTB–MPQ links in Germany, REFIMEVE in France, and the Italian LIFT network. The QTF Backbone will enable transformative Research and Development (R&D), support a nationwide QTF ecosystem, and ensure the transition from innovation to deployment. As a national and European hub, it will position Germany and Europe at the forefront of quantum networking, as well as T&F transfer.

•Jul 16, 2026•0 citations

European Metrology Network for Quantum Technologies

S. Bize

•Apr 16, 2024•0 citations

Abstract The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined to isolated testbeds, with quantum and T&F signals accessible, for example in Germany, to only a few institutions. In this white paper we propose the QTF Backbone: a dedicated national fibre-optic infrastructure in Germany for the networked distribution of Q uantum and T&F signals using dark fibres and specialised hardware. The QTF Backbone is planned as a four-phase deployment over ten years to ensure scalable, sustainable access for research institutions and industry. The concept builds on successful demonstrations of time and frequency distribution at high Technology Readiness Levels (TRLs) across Europe, including PTB–MPQ links in Germany, REFIMEVE in France, and the Italian LIFT network. The QTF Backbone will enable transformative Research and Development (R&D), support a nationwide QTF ecosystem, and ensure the transition from innovation to deployment. As a national and European hub, it will position Germany and Europe at the forefront of quantum networking, as well as T&F transfer.

White Rabbit (WR) technology provides a commercially-available off-the-shelf solution for time synchronisation with sub-nanosecond accuracy and picosecond-level precision over optical fibre links typically spanning tens of kilometres. Such high-performance time dissemination can support a variety of applications, including position, navigation and timing (PNT), financial transactions, metrology, as well as entanglement and quantum key distribution (QKD). Demonstrations of WR over significantly longer distances remain few and far between, particularly in scenarios where intermediate amplification is unavailable, such as stretches of long-haul underwater fibre. In this work, we report the longest unrepeated deployment of WR to date, achieving time synchronisation over a 300 km (51.34 dB) single-span optical fibre link, even in highly asymmetrical configurations, with 99.86% uptime, whilst maintaining picosecond-level precision and sub-nanosecond accuracy. This was achieved through careful selection and optimisation of the components deployed at the link's end points. By leveraging standard telecom fibre and off-the-shelf hardware, our results pave the way for a scalable and standardised timing backbone for large-scale quantum networks, offering a practical route toward time distribution in future heterogeneous quantum communication systems.

The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined to isolated testbeds, with quantum and T&F signals accessible, for example in Germany, to only a few institutions. In this white paper we propose the QTF Backbone: a dedicated national fibre-optic infrastructure in Germany for the networked distribution of Quantum and T&F signals using dark fibres and specialised hardware. The QTF Backbone is planned as a four-phase deployment over ten years to ensure scalable, sustainable access for research institutions and industry. The concept builds on successful demonstrations of time and frequency distribution at high Technology Readiness Levels (TRLs) across Europe, including PTB–MPQ links in Germany, REFIMEVE in France, and the Italian LIFT network. The QTF Backbone will enable transformative Research and Development (R&D), support a nationwide QTF ecosystem, and ensure the transition from innovation to deployment. As a national and European hub, it will position Germany and Europe at the forefront of quantum networking, as well as T&F transfer.