PUBLISHED: 05:29 EST, 24 April 2012 | UPDATED: 05:31 EST, 24 April 2012
A photon gun capable of firing single photons across a rainbow of colours is being heralded as a big step towards a quantum internet.
In such a system information is sent back and forth along fibre optic cables by individual photons. This method of data transfer will give us a considerably bigger and faster world wide web.
In theory a quantum internet is virtually unhackable, but for this to happen the photons need to be reliably fired one at a time.
If they travel in bunches hackers could glean information from the surplus photons.
However, researchers at the Max Planck Institute for the Science of Light in Erlangen, Germany have built a kind of photon ‘supergun’ that can fire photons in pairs.
The Physics arXiv Blog explained why this is significant.
It said: ‘The detection of one photon is an unambiguous sign that another has also been emitted. It’s like a time stamp that says a photon is on its way.
‘This so-called photon herald means that there can be no confusion over whether the gun is secretly leaking information to a potential eavesdropper.’
The gun can also emit photons across different colours, or wavelengths.
The arXiv blog adds: ‘That’s important because it means the gun can be tuned to various different atomic transitions allowing physicists and engineers to play with a variety of different atoms for quantum information storage.’
The gun is certainly a crucial step towards a quantum internet, and follows the news that another team at the Max Planck optics department actually built a baby version of one.
In their experiment the scientists succeeded in passing information from one photon to another.
The photons travelled along a 60-metre fibre optic cable that ran between two laboratories.
Team leader Stephan Ritter said: ‘We have realised the first prototype of a quantum network. We achieved reversible exchange of quantum information between the nodes.’