Scientists have broken the world record for quantum teleportation, transporting packages of light 60 miles (100km) over optical fibre. The record, which is four times farther than the previous mark, has been hailed as an important milestone in the quest for a high-speed and ultra-secure quantum internet.
The transfer of quantum information at the National Institute of Standards and Technology (NIST) in Colorado confirmed that quantum communication is feasible over long distances and holds huge potential for the emerging field of quantum computing. To achieve the record, a near-infrared wavelength commonly found in telecommunications was used together with advanced single-photon detectors.
What is quantum computing?
Quantum computers replace traditional bits that are used in digital communications with quantum bits, or qubits. Potential applications can be found in a variety of fields, from medicine to space travel.
Qubits exist in a state of superposition, meaning they can be in both states at once (zero and one), rather than being restricted to a single binary state in the way traditional computers function.
"What's exciting is that we were able to carry out quantum teleportation over such a long distance," Martin Stevens, NIST researcher and co-author of the study, told Live Science. "Only about 1% of photons make it all the way through 100 kilometres of fibre. We never could have done this experiment without these new detectors, which can measure this incredibly weak signal."
Quantum teleportation over longer distances has only been achieved in open space, however this is not practical in real-world communications. The latest study, published in the journal Optica, details how optical fibre could be used to create a quantum internet.
"If you wanted quantum teleportation in the real world — say, from one city to another — you might not necessarily have a direct line of sight between two locations," Stevens said. "You wouldn't want to be limited to working at night, so fibre optics might be more feasible.
"A quantum internet could allow you to establish communications channels that are much more secure than what we have with the standard encryption protocols we use everyday nowadays."