Engineers at Northwestern University have achieved the first successful demonstration of quantum teleportation over a fiber optic cable, a feat previously deemed nearly impossible. This significant advancement, funded by the U.S. Department of Energy, opens new avenues in quantum communication, enabling the integration of quantum and classical networks using existing internet infrastructure.
Quantum teleportation utilizes the phenomenon of quantum entanglement, allowing information to be transferred without physical transmission. As Prem Kumar, a leading researcher on the project, explains, “Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure.”
The research team developed a technique to isolate photons carrying quantum states from the multitude of classical information transmitted through the same cables. This innovation mitigates the interference that previously hindered quantum communication, enabling the transfer of quantum information over distances without direct transmission. “Teleportation allows the exchange of information over great distances without requiring the information itself to travel that distance,” says Jordan Thomas, the lead author of the study.
Conducting their experiments over a 30-kilometer fiber optic cable, the team successfully transmitted quantum information alongside high-speed internet traffic. The results confirmed that quantum information was transmitted effectively, despite the presence of classical signals. This breakthrough suggests that quantum connectivity could be established securely between geographically distant nodes without the need for dedicated infrastructure.
Looking ahead, the team aims to conduct experiments over longer distances and explore the potential of using two pairs of entangled photons, which could lead to further advancements in quantum applications. Their study, titled “Quantum teleportation coexisting with classical communications in optical fiber,” was published in the journal Optica.