Charlie Stross Called and Wants his Singularity Sky Concept Back

One possible future for communication is to create a quantum version of the internet that will have the ability, among other things, to send information with perfect security. This network will use entangled photons to transmit information from one locations to another without it passing through the space in between, hence the security.

Photons can only travel hundred kilometres or so through optical fibres before being absorbed. Conventional optical networks get around this with repeaters that boost the optical signal as it passes by.

This is more difficult with a quantum network but physicists have already tested many of the building blocks necessary to make quantum repeaters work. Nevertheless, quantum repeaters will be delicate pieces of kit, operating close to absolute zero with all the necessary cooling and power that is also required.

That should be relatively straightforward for quantum networks that stretch across land. But it is entirely unsuitable for undersea cables where conditions are far more hostile and the absence of infrastructure is a potential showstopper.

In fact, nobody is quite sure how it will be possible to operate the number of quantum repeaters necessary to carry one half of an entangled photon pair across the Atlantic or the Pacific. And without any technology even on the horizon that can do this job, there is a very real possibility that the quantum Internet might only ever consist of isolated quantum islands on different continents.

Today, Simon Devitt from Ochanomizu University in Japan and a few pals have come up with a way to solve this problem. Their idea is to transport the quantum bits or qubits across the ocean on a containership, a kind of quantum Clipper, that will shuttle back and forth across the seas with a ghostly quantum load.

link.