Scientists Transmit Quantum Entanglement Over 24km Fiber With Over 94% Fidelity
US-based scientists have successfully transmitted entangled photon pairs over a 24.4 km commercial fiber optic link, maintaining over 94% entanglement fidelity. This marks a significant step toward a quantum internet.
Scientists at Northwestern University have achieved a significant milestone in the development of a quantum internet by successfully transmitting entangled photon pairs over a 24.4-kilometer commercial fiber optic link. The experiment demonstrated the feasibility of sending quantum information through real-world fiber infrastructure.
The study, published in Optica Quantum, reported that the entanglement fidelity remained above 94% despite the fiber carrying substantial conventional internet traffic. This traffic level is equivalent to transmitting 36 terabits per second, comparable to 20 million YouTube videos simultaneously.
To overcome the challenges of noise and timing in a busy network, the researchers employed an optical timing system known as White Rabbit. This system synchronized the network's endpoints to a precision of one trillionth of a second, enabling the precise matching of entangled photon pairs.
This achievement suggests that quantum signals can maintain their integrity even when transmitted alongside high volumes of classical data. The team previously demonstrated quantum teleportation over 30 km of fiber in a laboratory setting and plans further experiments on metropolitan fiber networks carrying commercial traffic.