Researchers take a step towards quantum computing

Apr 19, 2010
Researchers take a step towards quantum computing

A team from Cardiff University's School of Physics and Astronomy fired light particles, or photons, into a tiny tower of semi-conducting material. A photon collides with an electron confined in an even smaller structure within the tower, and they oscillate briefly between the states of light and matter, before the photon re-emerges.

The Cardiff team have conducted this experiment with both individual and pairs of photons. They showed that photon pairs increase the frequency of the between and matter over individual photons. Their findings agree with theoretical predictions first made in the 1960s.

The findings have long-term implications for information and communications technology. It may one day be possible to build logical systems based on the interactions of these particles - also known as quantum computing. As the particles move faster and use less energy than conventional electronic computer components, this would lead to more efficient processing.

However, the technical problems involved are still extremely difficult. The Cardiff team used a semiconductor tube of 1.8 micrometers in diameter. It was kept at a temperature of around -263ºC (ten degrees above ) and the photons were trapped inside a tube only for around 10 picoseconds.

Professor Wolfgang Langbein, who led the team with Dr Jacek Kasprzak, now at Néel Institute, CNRS Grenoble, said: "This interaction can produce a steady stream of , and can also be the basis for single photon logic - which requires the minimum amount of energy to do logic. In the long term, there are implications in a number of areas, including computing, telecommunications and cryptography devices.

"To use this technology in real computing devices will take a significant improvement of the low-temperature properties and ideally its translation to room temperature. At the moment we have no clear concept how to do this - but it is not impossible."

The group's findings have just been published in Nature Materials. The world-class semiconducting structures used in the experiments were developed at the University of Würzburg in Germany.

Explore further: Good quantum states and bad quantum states

Related Stories

Quantum electronics: Two photons and chips

Jan 20, 2006

Scientists at Toshiba Research Europe Limited (Cambridge, UK) believe they are on to a way of producing entangled twins of photons using a simple semiconductor electronic device. Such a chip-based source of entangled photons ...

Mass weddings -- NIST's new efficient 2-photon source

Apr 12, 2007

For a variety of applications in physics and technology, ranging from quantum information theory to telecommunications, it’s handy to have access to pairs of photons created simultaneously, with a chosen ...

Shining light in quantum computing

Sep 12, 2006

University of Queensland scientist Devon Biggerstaff is investigating ways to manipulate light in a process that will help shape future supercomputers and communication technology.

Recommended for you

Good quantum states and bad quantum states

Jul 06, 2015

It is impossible to obtain all information about a large quantum system consisting of hundreds or thousands of particles. A new technique allows to describe such systems in terms of 'continuous matrix product ...

Soundproofing with quantum physics

Jul 02, 2015

Sebastian Huber and his colleagues show that the road from abstract theory to practical applications needn't always be very long. Their mechanical implementation of a quantum mechanical phenomenon could soon ...

Producing spin-entangled electrons

Jul 01, 2015

A team from the RIKEN Center for Emergent Matter Science, along with collaborators from several Japanese institutions, have successfully produced pairs of spin-entangled electrons and demonstrated, for the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.