Quantum teleportation breakthrough supercharges quantum technologies

Scientists from University College London in the UK have made a major breakthrough in quantum teleportation, which is just like it sounds – teleporting photons from A to B Star Trek style – and while I wrote about another successful Chinese quantum teleportation experiment that teleported photons a distance of 300km this time the team of researchers behind the latest experiment have teleported something far more complex than ever before. That said though, sorry, photons and matter are different and we are still a tremendously long way away from teleporting actual matter. Nevertheless, the latest experiment is very impressive and has far reaching implications for a number of reasons.

Quantum teleportation is a still mysterious phenomena that can see information flung across space. The effect is not the same as the teleportation often seen in science fiction – where matter is moved through space, but instead is the transfer information about the quantum state of a particle and it could have huge and unimagined effects on the way we organise and transmit information, including how we build out the first unhackable quantum internet that debuted last year.

Until now, scientists have only been able to teleport quantum bits, or qubits, like the ones being developed for use in ultra-powerful quantum computers. Qubits the simplest possible piece of quantum information, where a particle can be in two states at once.

But a Qutrit – which scientists have now successfully teleported – adds a whole extra dimension. If a qubit is polarised in two ways at once, a qutrit is polarised in three directions – a vastly more complicated unit, and a far greater challenge for the scientists involved.

It means, in effect, that scientists have more detailed information that can be teleported. Like binary a qubit can transmit information as either a 0 or a 1; but a qutrit can be 0, 1 or 2. And that opens the door to allowing us using them to transmit greater volumes of more complex information – a significant step up.

Sending a qutrit rather than a qubit means a vast increase in complexity, because of the nature of the process. But it also means that the effect could be far more useful.

“The higher the dimensions of your quantum system, the more secure you can ensure your communication is and the more information you can encode,” Ciarán Lee, from UCL, told New Scientist. “But going from a qubit to a qutrit is especially difficult — the tricks you use for qubits have to do with a nice symmetry that qutrits don’t have.”

The researchers report in their new paper, published in Physical Review Letters, that the demonstrations of their technique had a 75 per cent fidelity. That may appear low, but is far better than similar techniques that do not use quantum entanglement and is likely to improve in time.