Northwestern University Researchers Demonstrate Quantum Entanglement Over Busy Telecom Fiber

Northwestern University researchers demonstrated that entangled photons can be distributed over a 24.4-kilometer metropolitan fiber-optic link while the same cable simultaneously carried high-capacity commercial internet traffic, supporting the feasibility of quantum networks on existing telecommunications infrastructure. By transmitting quantum signals in the optical O-band, separating them from conventional C-band traffic, and using precise picosecond-level synchronization, the team preserved entanglement with more than 94% fidelity despite heavy data transmission. The researchers plan to build on the demonstration by performing quantum teleportation between remote nodes across a live metropolitan telecommunications network carrying commercial…