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

Liebisch TC, Kaufmann P, Schnatz H, Nägele-Jackson S, Kronjäger J, Blaum K, Kück S, Meschede D, Schiller S, Agazzi L, Alighanbari S, Ankerhold J, Astakhov GV, Barz S, Baumann I, Baumgart R, Becher C, Bekker H, Benson O, Bianco P, Bieber R, Bloch I, Blumröder U, Bockholt R, Bouman J, Braxmaier C, Brehm E, Bruss D, Budker D, Bungartz HJ, Busley E, Crespo López-Urrutia JR, Denz C, Deppe C, Dietl G, Ding F, Eickermann T, Elsen F, Ertmer W, Filipp S, Fischer M, Flury J, Fröhlich T, Furthner J, Gerhardt I, Giering KU, Glingener C, Grießer H, Grimm R, Grimm C, Gritsch A, Hack F, Hänsch T, Halfmann T, Hanemann A, Harlacher D, Hegemann N, Heindel T, Heinkelmann R, Hellmich L, Hildmann T, Hock D, Höfling S, Höft B, Hofmann H, Holleczek P, Holzwarth R, Hommel W, Hühn T, Hugentobler U, Hunger D, Huntemann N, Issever C, Jelezko F, Jöns K, Johann T, Jousset P, Jungbluth B, Kärtner F, Kankel J, Kaufmann H, Khabi D, Kissinger T, Klempt C, Klügel T, Kniggendorf AK, Kodet J, Konrad U, Kopp J, Kramer M, Kremling S, Krist M, Krutzik M, Kwasniok S, Leifels Y, Leuchs G, Lisdat C, Litvinov Y, Lochter M, Loock Pv, Lüsse P, Manske E, Mehlstäubler T, Michler P, Micke P, Migura M, Müller J, Nörtershäuser W, Pachnicke S, Paffrath R, Peik E, Pempe W, Peters A, Pfeifer T, Piester D, Pohl R, Rasel EM, Reiser H, Reiserer A, Rieck M, Riehle F, Ritter S, Rogge N, Ruiz Ben E, Sajith LPK, Sanchez L, Schäfer V, Schaefer W, Schieferdecker N, Schmidt P, Schnabel R, Schön S, Schreiber U, Schuck C, Schuh H, Schulz H, Schulz-Zander J, Schwanke U, Seifert JP, Sengstock K, Shafak K, Silberhorn C, Smorra C, Spethmann N, Steiert J, Stellmer S, Sterr U, Stöhlker T, Stuhler J, Sturm S, Thirolf PG, Tobeck C, Udem T, Ulmer S, Vasilyan S, Vincent A, Vogl T, Vogl R, Walther T, Weinfurter H, Weinheimer C, Wense Lvd, Wickenbrock A, Wörner L, Wolf F, Worm S, Yang Y, Zimmermann M, Zopf M (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Book Volume: 235

Pages Range: 3353–3387

DOI: 10.1140/epjs/s11734-026-02451-3

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 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.

Authors with CRIS profile

Involved external institutions

Physikalisch-Technische Bundesanstalt (PTB) Germany (DE) Max-Planck-Institut für Kernphysik (MPIK) / Max Planck Institute for Nuclear Physics Germany (DE) Rheinische Friedrich-Wilhelms-Universität Bonn Germany (DE) Heinrich-Heine-Universität Düsseldorf Germany (DE) Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) / German Aerospace Center Germany (DE) Universität Ulm Germany (DE) Helmholtz-Zentrum Dresden-Rossendorf (HZDR) Germany (DE) Universität Stuttgart Germany (DE) BHO Legal Germany (DE) eleQtron GmbH Germany (DE) Universität des Saarlandes (UdS) Germany (DE) Forschungszentrum Jülich / Research Centre Jülich (FZJ) Germany (DE) Deutsche Bahn AG Germany (DE) Max-Planck-Institute of Quantum Optics (MPQ) / Max-Planck-Institut für Quantenoptik Germany (DE) Technische Universität Ilmenau Germany (DE) Bundesamt für Kartographie und Geodäsie (BKG) / Federal Agency for Cartography and Geodesy Germany (DE) Deutsches Elektronen-Synchrotron DESY Germany (DE) Johannes Gutenberg-Universität Mainz (JGU) Germany (DE) Technische Universität München (TUM) Germany (DE) Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik (FHR) / Fraunhofer Institute for High Frequency Physics and Radar Techniques Germany (DE) Verein zur Förderung eines Deutschen Forschungsnetzes e. V. (DFN-Verein) Germany (DE) Humboldt-Universität zu Berlin Germany (DE) Technische Universität Braunschweig Germany (DE) Julius-Maximilians-Universität Würzburg Germany (DE) Gottfried Wilhelm Leibniz Universität Hannover Germany (DE) Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen Germany (DE) Menlo Systems GmbH Germany (DE) Technische Universität Berlin Germany (DE) Infosim GmbH & Co. KG Germany (DE) Karlsruhe Institute of Technology (KIT) Germany (DE) Universität der Bundeswehr München Germany (DE) Hochschule Nordhausen - University of Applied Sciences Germany (DE) Fraunhofer-Institut für Integrierte Schaltungen (IIS) Germany (DE) Adtran Networks Germany (DE) Adva Network Security GmbH Germany (DE) Universität Koblenz Germany (DE) Technische Universität Darmstadt Germany (DE) Technische Hochschule Lübeck (THL) / Technical University of Applied Sciences Lübeck Germany (DE) Universität Siegen Germany (DE) JoS QUANTUM GmbH Germany (DE) Universität Münster (ehem. Westfälische Wilhelms-Universität (WWU)) Germany (DE) Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum - GFZ Germany (DE) Universität Paderborn Germany (DE) Christian-Albrechts-Universität zu Kiel Germany (DE) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy Germany (DE) Ruhr-Universität Bochum (RUB) Germany (DE) GSI Helmholtzzentrum für Schwerionenforschung GmbH Germany (DE) Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light Germany (DE) BSI Bundesamt für Sicherheit in der Informationstechnik Germany (DE) Nokia (Germany) Germany (DE) Fraunhofer-Institut für Lasertechnik (ILT) Germany (DE) Cycle GmbH Germany (DE) Bayerische Akademie der Wissenschaften Germany (DE) TOPTICA Photonics AG Germany (DE) Universität Hamburg (UHH) Germany (DE) Ludwig-Maximilians-Universität (LMU) Germany (DE) NMWP.NRW NanoMikroWerkstoffePhotonik.NRW Germany (DE) TimeTech GmbH Germany (DE) SEFE Energy GmbH Germany (DE) Fraunhofer-Institut für Nachrichtentechnik (Heinrich-Hertz-Institut FhG HHI) Germany (DE)

How to cite

APA:

Liebisch, T.C., Kaufmann, P., Schnatz, H., Nägele-Jackson, S., Kronjäger, J., Blaum, K.,... Zopf, M. (2026). The QTF Backbone: proposal for a nationwide optical fibre backbone in germany for quantum technology and time and frequency metrology. European Physical Journal - Special Topics, 235, 3353–3387. https://doi.org/10.1140/epjs/s11734-026-02451-3

MLA:

Liebisch, Tara Cubel, et al. "The QTF Backbone: proposal for a nationwide optical fibre backbone in germany for quantum technology and time and frequency metrology." European Physical Journal - Special Topics 235 (2026): 3353–3387.

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