Captain Kirk's clone and the eavesdropper

Posted on 16 February 2006

Imagine Captain Kirk being beamed back to the Starship Enterprise and two versions of the Star Trek hero arriving in the spacecraft's transporter room.

It happened 40 years ago in an episode of the TV science fiction classic, and now scientists at the University of York and colleagues in Japan have managed something strikingly similar in the laboratory - though no starship commander was involved.

The first experimental demonstration of quantum telecloning has been achieved by scientists at the University of Tokyo, the Japan Science and Technology Agency, and the University of York. The work is reported in the latest issue of Physical Review Letters. Telecloning combines cloning (or copying) with teleportation (i.e., disembodied transport).

The scientists have succeeded in making the first remote copies of beams of laser light, by combining quantum cloning with quantum teleportation into a single experimental step. Telecloning is more efficient than any combination of teleportation and local cloning because it relies on a new form of quantum entanglement - multipartite entanglement.

Quantum mechanics allows us to do things which we previously thought were impossible

Professor Sam Braunstein

Professor Sam Braunstein, of the Department of Computer Science at York, said: "Quantum mechanics allows us to do things which we previously thought were impossible. In 1998, I was involved in an experiment in America which was one of the first for quantum teleportation in which we transmitted a beam of light without it crossing the physical medium in between.

"This new experiment is an extension of that work. Whether it will change the world for individuals or is just of use to governments or big companies is hard to say. Any new protocol is like a new-born baby and it has to develop, but we know this one could be used to tap cryptographic channels.

"Quantum cryptographic protocols are so secure that they can not only discover tapping but also where and how much information is leaking out. Now, using telecloning, the identity and location of the eavesdropper can be concealed."

Telecloning and teleportation may no longer be theories, but we are still a long way from teleporting people.

Professor Braunstein said: "What we know is that it would be incredibly difficult and from the perspective of today's technology, a completely outrageous thing. But in 100 years, who knows?"

Notes to editors:

  • The article "Demonstration of quantum telecloning of optical coherent states" is scheduled for publication in the February 17 issue of the scientific journal "Physical Review Letters". The full list of authors is: S.Koike, H.Takahashi, H.Yonezawa, N.Takei, Prof. S.L.Braunstein, T.Aoki and Prof. A.Furusawa.
  • Professor Braunstein joined the University of York in 2003. He is a recipient of the prestigious Royal Society-Wolfson Research Merit Award. He has over 80 scientific papers published in refereed journals, which have been cited over 3400 times. His work on quantum teleportation, quantum computation, quantum lithography and quantum information has received extensive coverage in prestigious scientific venues such as Science, Nature, Physics Today, New Scientist and Optics and Photonics News, as well as on radio, television and daily newspapers (The Independent, The Times, The New York Times and more) - see www-users.cs.york.ac.uk/~schmuel/NewsPR.html
  • The Department of Computer Science at the University of York was awarded the highest possible 6* grade by the Higher Education Funding Council for England (HEFCE) in 2003. The department attracts more industrial funding for academic research in computing than any other department in the UK. Teaching in the Department of Computer Science was recently judged excellent by HEFCE. The Department has 400 undergraduates, 100 taught postgraduates and 100 full-time research students. The British Computer Society and the Institution of Electrical Engineers accredit the Department's courses. See www.cs.york.ac.uk/public.php
  • The episode of Star Trek in which two Captain Kirks were created, due to a transporter malfunction, was called The Enemy Within which was first broadcast in the USA on 6 October 1966.

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