Boost for the quantum internet

In order to transmit quantum information over long distances, so-called quantum repeaters are needed to distribute entanglement over long distances.
(c) Harald Ritsch / Universität Innsbruck

First long-distance quantum repeater node for telecommunication networks.

A quarter of a century ago, theoretical physicists at the University of Innsbruck, Austria, made the first proposal on how to transmit quantum information via quantum repeaters over long distances which would open the door to the construction of a worldwide quantum information network. Now, a new generation of researchers at the University of Innsbruck has built a quantum repeater node for the standard wavelength of telecommunication networks and transmitted quantum information over tens of kilometers.

Quantum networks connect quantum processors or quantum sensors with each other. This allows tap-proof communication and high-performance distributed sensor networks. Between network nodes, quantum information is exchanged by photons that travel through optical waveguides. Over long distances, however, the likelihood of photons being lost increases dramatically. As quantum information cannot simply be copied and amplified, 25 years ago Hans Briegel, Wolfgang Dür, Ignacio Cirac and Peter Zoller, then all at the University of Innsbruck, provided the blueprints for a quantum repeater. These feature light-matter entanglement sources and memories to create entanglement in independent network links that are connected between them by a so-called entanglement swap to finally distribute entanglement over long distances.

Even transmission over 800 kilometers possible

Quantum physicists led by Ben Lanyon from the Department of Experimental Physics at the University of Innsbruck have now succeeded in building the core parts of a quantum repeater — a fully functioning network node made with two single matter systems enabling entanglement creation with a photon at the standard frequency of the telecommunications network and entanglement swapping operations. The repeater node consists of two calcium ions captured in an ion trap within an optical resonator as well as single photon conversion to the telecom wavelength. The scientists thus demonstrated the transfer of quantum information over a 50-kilometer-long optical fiber, with the quantum repeater placed exactly halfway between starting and end point. The researchers were also able to calculate which improvements of this design would be necessary to make transmission over 800 kilometers possible which would allow to connect Innsbruck to Vienna.

The current results were published in Physical Review Letters. Funding for the research was provided by a START award from the Austrian Science Fund FWF, the Austrian Academy of Sciences and the European Union, among others. Lanyon’s team is part of the Quantum Internet Alliance, an international project under the EU Quantum Flagship.

Wissenschaftliche Ansprechpartner:

Ben Lanyon
Department of Experimental Physics
University of Innsbruck
+43 512 507 52900


Telecom-wavelength quantum repeater node based on a trapped-ion processor. V. Krutyanskiy, M. Canteri, M. Meraner, J. Bate, V. Krcmarsky, J. Schupp, N. Sangouard, and B. P. Lanyon. Phys. Rev. Lett. 130, 213601 DOI: [arXiv:]

Quantum Repeaters: The Role of Imperfect Local Operations in Quantum Communication
H.-J. Briegel, W. Dür, J. I. Cirac, and P. Zoller. Phys. Rev. Lett. 81, 5932 – Published 28 December 1998 [arXiv:]

Weitere Informationen: – Physics: Quantum Repeater Goes the Distance

Media Contact

Dr. Christian Flatz Büro für Öffentlichkeitsarbeit
Universität Innsbruck

All latest news from the category: Information Technology

Here you can find a summary of innovations in the fields of information and data processing and up-to-date developments on IT equipment and hardware.

This area covers topics such as IT services, IT architectures, IT management and telecommunications.

Back to home

Comments (0)

Write a comment

Newest articles

ispace and University of Leicester collaborate on lunar night survival technology

ispace, inc. (ispace), a global lunar exploration company, and the University of Leicester, have agreed to collaborate on approaches to lunar night survivability for future ispace lunar lander and rover…

Technique to analyze RNA structures in ultra-high definition

This is where the Nottingham team, led by Dr Aditi Borkar, Assistant Professor in Molecular Biochemistry & Biophysics in the School of Veterinary Medicine and Science, has achieved a transformative…

Iron could be key to less expensive, greener lithium-ion batteries

What if a common element rather than scarce, expensive ones was a key component in electric car batteries? A collaboration co-led by an Oregon State University chemistry researcher is hoping…

Partners & Sponsors