"Mother of All Quantum Networks" Unveiled in Vienna

EU-sponsored quantum-cryptography network unparalleled in size and complexity

3 min read

22 October 2008—Vienna has been the backdrop of some major milestones in the new science of quantum cryptography, and on 8 October, the city made its mark again. Scientists there have booted up the world’s largest, most complex quantum-information network, in which transmitted data is encoded as the quantum properties of photons, theoretically making the information impervious to eavesdropping.

Built at a cost of 11.4 million euros, the network spans approximately 200 kilometers, connecting six locations in Vienna and the neighboring town of St. Poelten, and has eight intermediary links that range between 6 and 82 km. The new network demonstrated a first for the technology—interoperability among several different quantum-cryptography schemes. The project, which took about six months longer to complete than planned, was so complex that some wags are calling the Viennese network ”the mother of all quantum networks.”

Keep Reading ↓Show less

This article is for IEEE members only. Join IEEE to access our full archive.

Join the world’s largest professional organization devoted to engineering and applied sciences and get access to all of Spectrum’s articles, podcasts, and special reports. Learn more →

If you're already an IEEE member, please sign in to continue reading.

Membership includes:

  • Get unlimited access to IEEE Spectrum content
  • Follow your favorite topics to create a personalized feed of IEEE Spectrum content
  • Save Spectrum articles to read later
  • Network with other technology professionals
  • Establish a professional profile
  • Create a group to share and collaborate on projects
  • Discover IEEE events and activities
  • Join and participate in discussions

The Future of Deep Learning Is Photonic

Computing with light could slash the energy needs of neural networks

10 min read
Image of a computer rendering.

This computer rendering depicts the pattern on a photonic chip that the author and his colleagues have devised for performing neural-network calculations using light.

Alexander Sludds

Think of the many tasks to which computers are being applied that in the not-so-distant past required human intuition. Computers routinely identify objects in images, transcribe speech, translate between languages, diagnose medical conditions, play complex games, and drive cars.

The technique that has empowered these stunning developments is called deep learning, a term that refers to mathematical models known as artificial neural networks. Deep learning is a subfield of machine learning, a branch of computer science based on fitting complex models to data.

Keep Reading ↓Show less