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TU Delft has a breakthrough in quantum internet: how does that work?

A major breakthrough has been made at TU Delft. Researchers have succeeded in making a well-functioning quantum connection that can be used for a future form of the internet. That is a bit complicated, but let’s keep it simple. Quantum connection runs on the idea that – for reasons that nobody understands, even though it does work – there is a connection between two quantum particles. That is called quantum entanglement, or entanglement. Again: how that works is unclear, but it works.

How does quantum internet work?

So that is bizarre, but it also means that you can send data through that system. After that entanglement between the particles is established, two light particles are released that are also entangled. Then you can move one of the two light particles in all sorts of ways, because sending light, we could already do that. It is possible through our fiber optic connection, but it can also be radiated via satellite. That is even better, because at the moment there is noise when you move the particles through fiber and it does not come that far.

And now comes the trick: that quantum state of those particles has the remarkable property that if you do something with it (such as looking at it, or copying the particle) the particle changes. So you can check if a particle arrives or if it has been sent undisturbed and you can be sure that no one has seen the ‘data’. This makes it virtually impossible to intercept and that would mean that in any case no data can be intercepted between sender and receiver.

What did TU Delft do then?

Research into these quantum particles is already under way in various countries and laboratories, but TU Delft has now made a big step in entangling the particles. That was still in the heavily experimental phase and it took forever (especially in internet terms) to intertwine two particles. A new technique now makes it possible to entangle a particle up to forty times per second and then you are at a speed that you can really start testing with quantum internet.

Of course that’s the next thing they’re going to do, so a connection is now being established between Amsterdam, Delft, Leiden and The Hague. It should be functional by 2020. In the four cities a kind of extremely strong fridges will be put down which are needed to intertwine particles and these will then be connected to the regular optical fiber network. That is where the interlaced light particles go through and if that all works according to plan, there is a start of the quantum internet.


Hopefully they are the first. Indeed, researchers at MIT and in a lab in China are also quite far behind. There was also a demonstration earlier of sending quantum particles via satellite by a Chinese party. Satellites are extra interesting, because the noise that occurs when sending the light particles does not occur in the vacuum of the room. Quantum entanglement has tremendous potential, but for now it would be a feast if we can stably and consistently set up this form of communication and with a bit of luck this will soon be the first in the Netherland.

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