WHY THIS MATTERS IN BRIEF
Teleportation is the ultimate sci-fi dream, and scientists are getting better at teleporting quantum particles further than ever before but teleporting real objects is still a long way away.
Earlier this week Chinese scientists managed to teleport an object from Earth and into space, to a satellite orbiting 300 miles above the Earth, and in the process they set a new record for quantum teleportation – an eerie phenomenon where the complete properties of one particle are instantaneously transferred to another, in effect teleporting it to a distant location.
Scientists around the world have hailed it as a significant step towards the goal of creating an unhackable quantum internet, something that, for a number of reasons, the Chinese government has been pursuing with vigour for the past decade or so now, and over the course of the past year they’ve made breakthrough after breakthrough. First they built a 2,000km long unhackable quantum network across a fiber link, and recently they successfully tested the world’s first quantum satellite network. Next year it’s likely they’ll be the first country to create an international quantum network between China and Austria when they ramp up tests of their new satellite system again.
“Space scale teleportation can be realised and is expected to play a key role in the future distributed quantum internet,” wrote the researchers, who were led by Professor Chao-Yang Lu from the University of Science and Technology of China, the same university responsible for the other breakthroughs, in a paper.
While the latest experiment might get everyone breaking out the Star Trek analogies I’m sorry to disappoint you – we’re still a long way away from teleporting physical objects, and today the teleportation effect is limited to quantum scale objects, such as photons.
Sorry about that. One day though…
In the experiment, the team beamed photons from a ground station in Ngari in Tibet to China’s Micius satellite, which is in orbit 300 miles above Earth.
The experiment hinged on a bizarre effect known as quantum entanglement, where which pairs of particles are generated simultaneously meaning they inhabit a single, shared quantum state. Counter intuitively, this inter-twined existence continues, even when the particles are separated by vast distances, and any change in one will affect the other.
As a result scientists have been able to exploit this effect to their advantage to transfer information between the two entangled particles. In quantum teleportation though a third particle is introduced and entangled with one of the original pair, in such a way that its distant partner assumes the exact state of the third particle. For all intents and purposes, the distant particle then takes on the identity of the new particle that its partner interacted with. And voila – instant teleportation. Dang scientists are clever.
In the future quantum teleportation could be harnessed to produce a new unhackable quantum communication networks where the information would be encoded by the quantum states of entangled photons, rather thantoday’s binary strings of 0’s and 1’s. The huge security advantage would be that it would be impossible for an eavesdropper to measure the photons’ states without disturbing them and revealing their presence, although a little while ago, in another world first, scientists from Canada announced they’d managed to hack a quantum network – something that technically should be impossible. But as regular readers of my blog should know by now impossible is two letters two long…
Ian Walmsley, Hooke professor of experimental physics at Oxford of University, said the latest work was an impressive step towards this ambition.
“This palpably indicates that the field isn’t limited to scientists sitting in their labs thinking about weird things. Quantum phenomena actually have a utility and can really deliver some significant new technologies,” he said.
Scientists around the world, such as a team from the National Institute of Standard and Technology (NIST) in America, have already succeeded in creating small scale quantum networks that allow secure messages to be sent over fibre optic links, but quantum entanglement is fragile and is gradually lost as photons travel through the fiber, meaning that scientists have struggled to get teleportation to work across large enough distances to make a global quantum network viable.
The advantage of using a satellite is that the particles of light travel through space for much of their journey instead of solid objects, but transmitting into space comes with its own challenges because the turbulence in the Earth’s atmosphere can interfere with the particles.
The Chinese teams latest paper, published on the Arxiv website, describes how, over a period of more than 32 days, the scientists sent millions of photons to the satellite and achieved teleportation in 911 cases.
“This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” they wrote, and while other countries, such as Canada, Germany, the UK, the US are all trying to develop their own quantum communications technology it looks like, once again, the Chinese has stolen a march on them all.
Beam me up. I’m done.