A team of researchers from the National Institute of Standards and Technology has broken the distance record for quantum teleportation down optical fibre, showing they’re able to transfer quantum information over 102 kilometres.
The researchers have shown that they can perform quantum communication, often performed in free space, over standard fibre-optic lines. It means they have been able to move the information down fibre four times farther than the previous record, which is an attractive proposition for those aiming to create a quantum internet.
Quantum teleportation isn’t quite the matter-shifting technique of Star Trek, but instead the process of transferring — in fact scientists say ‘remotely reconstructing’ — information that’s held in the quantum state of one chunk of matter or light to another, some distance away. The NIST scientists have shown that they can transfer the quantum state from one photon, down 102 kilometers of spooled optical fibre in the lab, to another photon. The experiment is reported in Optica, and the infographic below does a nice job of describing how the team achieved the result.
It may sound like a logical step to send quantum information down fibre optic cable — after all, it’s how much of the world’s data is now sent. But it was only made possible at such distances by a new type of single-photon detector developed at NIST. “Only about 1 per cent of photons make it all the way through 100 km of fibre,” explains Marty Stevens, a NIST researcher, in a press release. “We never could have done this experiment without these new detectors, which can measure this incredibly weak signal.”
Quantum teleportation is thought to be a promising route to developing quantum encryption — theoretically an unbreakable system where quantum states are used to hide data. But there’s a little work to be done before this technique can be used to achieve such a goal: the researchers can only achieve teleportation in 25 per cent of transmissions at best, and 102 kilometres may be a long way but it’s dwarfed by the scale of fibre optic cables used to transmit data across the Internet. Still, it’s good to have targets, right?