Scientists are approaching to make super-secure and fast quantum internet possible: they have now been able to “teleport” high-fidelity quantum information to a total distance of 44 kilometers (27 miles).
Both data fidelity and transfer distance are crucial in building a real and functional quantum Internet, and advancing in any of these areas is a cause for celebration for those building our next-generation communications network.
In this case, the team achieved a level of fidelity (data accuracy) higher than 90% with its quantum information, in addition to sending it through extensive fiber optic networks similar to those that constitute the backbone of our existing Internet.
“We are delighted with these results,” says physicist Panagiotis Spentzouris, of Fermilab’s particle and accelerator physics lab based at the California Institute of Technology (Caltech).
“This is a key achievement on the road to building a technology that will redefine the way we conduct global communication.”
Internet quantum technology uses qubits; unmeasured particles that remain suspended in a mixture of possible states, such as dice that are still spinning to solve.
The quubits that are introduced have their identity “tangled” in ways that become evident once they are finally measured. Imagine these intertwined qubits as a pair of dice; although each can land in any number, both are guaranteed to add up to seven, no matter how far apart they are. Data in one location instantly reflects data in another location.
By a clever disposition to entangle three qubits, it is possible to force the state of one particle to adopt the “roll of dice” of another through its mutually intertwined companion. In quantum earth, this is as good as turning one particle into another, teleporting its identity remotely in a blink.
Although the entanglement has yet to be established at first, and then maintained as the qubits are sent to their eventual destination via fiber optics (or satellites).
The unstable and delicate nature of quantum information makes it difficult to emit tangled photons over long distances without interference. Longer fiber optics simply mean more opportunities for noise to interfere with tangled states.
In total, the fiber lengths used to channel each centimeter were added to 44 kilometers, setting a new limit on the distance at which we can send interlaced qubits and still use them to teleport quantum information.
It has never been proven to work at such a long distance with such precision and bring an urban-sized quantum network closer to reality, although there are still years of work to make it possible.
“With this demonstration we begin to lay the groundwork for the construction of a metropolitan quantum network in the Chicago area,” says Spentzouris.
Quantum entanglement and data teleportation are a complex science, and not even experts fully understand how it could be used in a quantum network. However, every proof of concept like this puts us a little closer to making this network a reality.
In addition to promising huge increases in computing speed and power, a quantum Internet would be ultra-secure: any attempt at piracy would be as good as destroying the lock being chosen. For now, at least, scientists think that quantum Internet networks will act as specialized extensions to the classic Internet, rather than completely replace them.
Researchers face quantum Internet problems from all angles, so you’ll see several distances mentioned in the studies – not all measure the same technology, use the same equipment, to test the same standards.
What makes this study special is the accuracy and distance of the interlaced quantum teleportation, as well as the “off-platform” equipment used: theoretically it should be relatively easy to expand this technology using the hardware we already have. . .
“We are very proud to have achieved this milestone in sustainable, high-performance and scalable quantum teleportation systems,” says physicist Maria Spiropulu of Caltech.
“The results will be further improved with the system updates we hope to complete by the second quarter of 2021.”
The research has been published in As a PRX.