Quantum Communications Inch Closer

A few years back, I went to one of the New York Science Fair talks where a physicist described quantum entanglement and how changes to one particle appeared to be reflected by the other, simultaneously, regardless of the distance between the two. If I’m remembering this right, it was a while ago now, he brought this up as an example of how we might be able to send deep space robots to other stars but still be able to communicate with them in real time once they’ve arrived.

Needless to say, I thought this was awesome.

A graphic illustrating the concept of quantum communications

Naturally, I also began wondering how this could be used within the Unified Republic of Stars storyworld. And thus this article on interstellar communication was born. The principle is exactly as described by the physicist I heard speak: Particles are entangled and half are placed in a communications station while the others are put aboard a ship (usually military like the NOVA because of the overhead in doing so) or a communication relay buoy and then messages are sent back “digitally” with each spinning “up” or “down” of the particle counting as a bit.

In theory, it’s incredibly simple if one has a way of entangling particles and then observing them correctly to both send and receive messages. And… therein lies the problem.

From the Wired article where they describe the success researchers have been having trying to make a quantum communications network:

[..] the researchers still needed a complete lab room full of lasers, optical elements, and other equipment for each node. Each atom sat between two highly reflective mirrors 0.5 mm apart, which form an “optical cavity.” By applying an external laser to atom A, Ritter’s team caused a photon emitted by that atom to escape from its cavity and travel through a 60-meter-long optical fiber to the cavity across the street. When the photon was absorbed by atom B, the original quantum information from the first atom was transferred to the second. By starting with just the right state of the first atom, the researchers could entangle the two atoms.

So, needless to say, this is not something we can do at home yet. And the technology is still in its infancy. But the possibilities are amazing.

With quantum communications, since they happen theoretically simultaneously regardless of where the particles are, lag between two calls, be they on different sides of the world or between Earth and Mars would be completely eliminated. And, because this is the crux of the article above, they would also be totally secure if you controlled both sides of the network since there’s no way to intercept the “transmission” between two entangled particles.

This is a big reason why in the URS storyworld, warships use quantum entanglement as their communication systems. They can describe ship movements in plain language without ever having to worry about having their messages listened in on by the enemy.

But what’s really fascinating is that if researchers can now entangle particles across the street from one another, they can theoretically entangle them across much larger distances making something that was science-fiction science fact.

Does anyone else have any ideas for other uses of quantum entanglement? If you could flip a switch over massive distances, what kind of applications do you see it being used for?