US Tests First Real-World Quantum Internet on Fiber Network
U.S. Scientists Successfully Test First Real-World Quantum Internet On Commercial Fiber Network
Researchers at Northwestern University have achieved the first real-world demonstration of quantum entanglement over an active commercial fiber-optic network. The experiment sent quantum signals through the same fiber carrying high-speed internet traffic. The breakthrough could accelerate the development of a practical quantum internet.
The team distributed entangled photons over a 24.4-kilometer fiber link connecting Northwestern’s Evanston campus with downtown Chicago. The same cable simultaneously carried two 800-gigabit-per-second data channels and additional traffic representative of a fully loaded commercial network. Despite the heavy data flow, the quantum signals remained intact with more than 94% fidelity.
Quantum entanglement links two particles so that they remain correlated even when separated by long distances. Scientists have long believed these fragile quantum states would be disrupted by noise from conventional internet traffic. The new experiment shows that quantum and classical communications can successfully coexist on the same optical fiber.
To protect the delicate photons, the researchers placed them in a quieter region of the optical spectrum known as the O-band. They also used advanced filtering and routing methods to minimize interference. This allowed ordinary internet data and quantum signals to travel together without affecting each other.
The achievement could greatly reduce the cost of building future quantum networks. Instead of installing dedicated fiber-optic infrastructure, telecom providers may be able to upgrade existing networks to support quantum communication. This would make large-scale deployment faster and far more economical.
A future quantum internet could enable virtually unbreakable encryption, secure communication between quantum computers, distributed quantum computing, and ultra-precise synchronization for scientific instruments. These capabilities could transform cybersecurity, finance, healthcare, defense, and advanced research.
The research was published in Optica Quantum and represents a major step beyond laboratory testing. Scientists say many challenges remain, including longer transmission distances, scalable quantum repeaters, and connecting large numbers of quantum devices. Even so, the successful test on a busy commercial telecom network shows that practical quantum networking is steadily moving toward real-world deployment.
Sources:
- Northwestern University – Illinois
- Quantum Institute
