NIST researchers and collaborators successfully transmitted entangled photons over 62 kilometers of existing above-ground fiber infrastructure in Maryland, demonstrating that quantum networking can work on real-world telecom fiber. The team used real-time polarization stabilization hardware from Qunnect to counteract environmental disturbances — temperature changes, wind, and vibration — that would otherwise destroy the fragile quantum states. The experiment achieved a distribution rate of 1,500 entangled photon pairs per second and maintained entanglement 92.8% of the time over a 24-hour period. While not a distance record, the study is notable for using exposed, above-ground fiber under realistic noisy conditions, serving as a practical stress test for future quantum network deployments.
