ZAP // Dall-E-2
Engineers at Northwestern University are the first to successfully demonstrate quantum teleportation via a fiber optic cable carrying Internet traffic.
The discovery, in the journal Optica, introduces the new possibility of combining quantum communication using existing internet cables — greatly simplifying the infrastructure needed for advanced sensing technologies or quantum computing applications.
“That is incredibly excitingbecause no one thought it was possible,” he said Prem Kumara Northwestern researcher who led the study, in one at the university.
“Our work shows a path to the next generation of quantum and classical networks that share a unified fiber optic infrastructure. Basically, it opens the door to take quantum communications to the next level“, added the investigator.
An expert in quantum communications, Kumar is a professor of electrical engineering and computer science at Northwestern’s McCormick School of Engineering, where he directs the Center for Photonic Computing and Communication.
How it works
Limited only by the speed of light, quantum teleportation allows for a new form, ultra-fast and secureto share information between users on distant networks, where direct transmission is not necessary.
The process works by taking advantage of , a technique in which two particles are linked, regardless of the distance between them.
At the heart of this idea is the phenomenon of ““, a term coined by Albert Einstein to describe quantum entanglement.
This strange but fundamental principle of quantum mechanics suggests that “quantum interconnected particles”, who initially interactedthey can instantly influence each other’s propertiesregardless of the distance that separates them.
This phenomenon, which allows physicists to introduce changes in the characteristics of certain particles, causing the same changes, at a distancein particles that had previously interacted with the first ones, is the basis of quantum computing.
Thus, instead of particles physically traveling to transmit information, particles tangled, or intertwinedexchange information over great distances — without physically transporting them.
“In optical communications, all signals are converted into light,” Kumar explained. “While conventional signals for classical communications are typically composed of millions of light particles, the transport of quantum information use unique photos“.
“By performing a destructive measurement on two photons — one with a quantum state and the other entangled with another photon — the quantum state is transferred for the remaining photon, which could be very far away,” said Jordan Thomas, a doctoral candidate in Kumar’s lab and first author on the paper.
“The photon itself does not have to be sent long distances, but its state ends up being encoded in the photon at a distance. Teleportation allows the exchange of information over great distances without the information itself needing to travel that distance”, explains the researcher.
Before Kumar’s new study, many researchers they weren’t sure that quantum teleportation was possible in cables that carry classical communications.
Entangled photons would drown among the millions of other particles of light. It would be like a rickety bicycle trying to navigate a tunnel packed with heavy trucks at high speed.
Kumar and his team, however, have discovered a way to help the delicate photons stay away from heavy traffic.
After carrying out in-depth studies on how light disperses in fiber optic cables, researchers found a wavelength less crowded light source to place your photons. They then added special filters to reduce noise from normal Internet traffic.
“We carefully studied the way light scatters and placed our photons in a judicial point where this dispersion mechanism is minimized“, explains Kumar. “We discovered that we could perform quantum communication without interference from the classical channels that are simultaneously present.”
“Quantum teleportation has the ability to provide quantum connectivity safely between geographically distant nodes”, explains Kumar.
“Many people assumed that no one would build an infrastructure specialized to send light particles. If we choose the wavelengths correctly, we won’t have to build new infrastructure. Classical and quantum communications can coexist”, he concludes.
