Northwestern University engineers have successfully demonstrated quantum teleportation over fiber optic cables actively carrying Internet traffic, marking a significant step toward practical quantum communication networks that could use existing infrastructure.
Published in Optica | Estimated reading time: 4 minutes
“This is incredibly exciting because nobody thought it was possible,” said Northwestern’s Prem Kumar, who led the study. “Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level.”
The achievement overcomes a key challenge in quantum networking – the need for dedicated infrastructure. Until now, many researchers doubted quantum teleportation could work in cables carrying regular Internet traffic, as the delicate quantum signals would be overwhelmed by the millions of photons carrying classical data.
Kumar’s team succeeded by carefully studying how light scatters within fiber optic cables and identifying wavelengths where quantum signals could travel undisturbed. Jordan Thomas, a Ph.D. candidate and the paper’s first author, explains: “By performing a destructive measurement on two photons — one carrying a quantum state and one entangled with another photon — the quantum state is transferred onto the remaining photon, which can be very far away.”
The researchers tested their system over a 30-kilometer fiber optic cable while simultaneously transmitting 400 gigabit-per-second Internet traffic. The quantum information was successfully teleported even with busy Internet traffic flowing through the same cable. This suggests quantum communication could potentially be implemented using existing telecommunications infrastructure rather than requiring separate dedicated quantum networks.
Kumar and his team are now working to extend the experiments over longer distances and explore more complex quantum operations. Their success offers a promising pathway toward practical quantum networks that could enable ultra-secure communication and enhanced computing capabilities.
Glossary:
- Quantum Teleportation: A technique that transfers quantum information between particles without physically transmitting the particle itself
- Entanglement: A quantum phenomenon where two or more particles become linked so that the quantum state of each can’t be described independently
- Photon: The fundamental particle of light, used to carry both classical and quantum information
Test Your Knowledge
What type of traffic was running through the cable during the quantum teleportation?
400 gigabit-per-second Internet traffic
What is the key advantage of this new method?
It allows quantum communication to use existing fiber optic infrastructure instead of requiring dedicated quantum networks
How did the researchers solve the problem of quantum signals being overwhelmed by classical Internet traffic?
They studied how light scatters in fiber optic cables and identified specific wavelengths where quantum signals could travel undisturbed by classical data
What role does entanglement play in the quantum teleportation process?
Entanglement allows the quantum state to be transferred between particles through a destructive measurement, without the need for direct transmission of the particle carrying the original state
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