Northwestern University engineers have successfully demonstrated quantum teleportation over a fiber optic cable carrying Internet traffic for the first time. The breakthrough, published in the journal Optica, opens up new possibilities for combining quantum communication with existing internet cables.
Prem Kumar, a professor of electrical and computer engineering at Northwestern’s McCormick School of Engineering, led the study. “This is incredibly exciting because nobody thought it was possible,” he said. “Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure.”
Quantum teleportation enables fast and secure information sharing between distant network users without direct transmission. It works by harnessing quantum entanglement, where two particles are linked regardless of distance. The process involves converting signals to light and transferring the quantum state onto a photon that can be far away.
To overcome previous limitations, Kumar’s team studied how light scatters within fiber optic cables and found a less crowded wavelength for their photons. They added special filters to reduce noise from regular internet traffic.
The researchers tested the new method by sending quantum information and high-speed internet traffic through a 30-kilometer-long fiber optic cable. They successfully transmitted the quantum information, even with busy internet traffic present.
Kumar plans to extend experiments over longer distances and explore entanglement swapping, another important milestone for distributed quantum applications. His team is also investigating experiments over real-world optical cables rather than in the lab.
The breakthrough demonstrates that quantum teleportation can provide secure connectivity between geographically distant nodes without requiring specialized infrastructure. By choosing the right wavelengths, classical and quantum communications can coexist.
Source: https://news.northwestern.edu/stories/2024/12/first-demonstration-of-quantum-teleportation-over-busy-internet-cables