A new world record for quantum teleportation has been set, bringing quantum communication networks that can stretch between cities a step closer. Two independent teams have transferred quantum information over several kilometres of fibre optic networks.
Being able to establish teleportation over long distances is a crucial step towards exchanging quantum cryptographic keys needed for encoding data sent over the fibres.
Quantum teleportation is a phenomenon in which the quantum states of one particle can be transferred to another, distant particle without anything physical traveling between them. It relies on a property called entanglement, in which measuring the state of one particle immediately affects the state of its entangled partner, regardless of the distance between them.
So yes, quantum information moves faster than light, which has been demonstrated time after time and would be tested again under Ursin’s proposed experiment. There’s a catch, though, as there always seems to be with quantum physics; it does not appear to be possible to exploit this physical loophole in order to transmit information faster than the speed of light, because quantum properties are, once they are measured, utterly random. In other words, while quantum information can move faster than light, no other kind of information can. (To be fair, this is the subject of intense debate among experts, hardly a settled matter.)
There are ways to encrypt information using quantum entaglement, though, but that information can only be decrypted using traditional (subluminal) communication. Though it doesn’t bring us any closer to an ansible, this is still incredibly useful. Without getting into the headache-inducing details, it is possible to “quantum encrypt” information is such a way that anyone attempting to intercept it (referred to in much of the literature on the subject as “Eve,” as in “eavesdropper”) would be unable to hide her interference. This kind of quantum encryption isn’t just theoretical, either; it’s already been proven in the real world and is already in limited use to transmit extremely classified and secret information by a handful of government agencies and wealthy corporations.
Some physicists claim that quantum entanglement can transport information faster than light, and some claim that it can’t.
There is no guarantee that any of this will ever have any practical use. But if we can use it to share mp3s, it would be appropriate to load up the quantum network with lots of techno music.