Quantum Photons Survive a 24-Kilometer Journey Through Chicago’s Busy Internet

Northwestern researchers sent entangled photons between Evanston and downtown Chicago over existing telecom fiber carrying live data traffic.

The photon pairs preserved more than 94% fidelity across 24.4 kilometers, showing strong correlation in a real commercial network.

The result suggests quantum signals can survive on today’s installed internet infrastructure, without requiring separate fiber.

That could lower deployment costs and speed up practical quantum communication and teleportation systems.