The quantum internet has long had an awkward practical problem: it seemed to need its own dedicated cables. New work out of Northwestern University suggests it may not.
According to Tech Times, Northwestern researchers demonstrated that entangled photons — the fragile particles that carry quantum information — can travel through existing commercial telecom cables at the same time as ordinary internet traffic. The reported test covered 15 miles and preserved the quantum signal at 94% fidelity.
Those two numbers are the whole story. Fidelity is a measure of how intact the quantum state arrives; entanglement is notoriously easy to destroy, and a busy fiber carrying conventional data is a noisy, hostile place for it. Getting 94% while sharing a line with live traffic is the difference between a laboratory curiosity and something an existing network operator could plausibly build on.
The alternative — laying a parallel, quantum-only fiber network across cities and countries — is the kind of infrastructure project that takes decades and enormous capital. Reusing what is already buried in the ground changes the economics considerably.
The result lands amid broader momentum in the field, which Electronics360 frames in a piece titled simply "The quantum communications revolution."
A note on limits: 15 miles is a metro-scale distance, not an intercity or transcontinental one, and the available reporting does not detail how the approach scales further.
Why it matters: if quantum links can share the fiber already running under our streets, the technologies they enable — communications secured by the laws of physics, and networks connecting quantum computers — get years closer and far cheaper than a from-scratch buildout would allow.