Quantum Link Tested Across New York Fiber * Science and Technology Times

Cisco and Qunnect have demonstrated a functioning quantum network running over existing fiber‑optic infrastructure between Brooklyn and Manhattan.
The experiment showed that quantum signals can remain stable in real‑world conditions, addressing key challenges for future quantum communication systems.
Their work is viewed as an early step toward practical quantum networks and, eventually, a quantum internet.

Real‑World Quantum Networking Demonstrated

Cisco and Qunnect announced that they successfully built and operated a quantum network across New York City using standard fiber‑optic cables. The test connected Brooklyn and Manhattan over a 17.6‑kilometer route, showing performance comparable to controlled laboratory environments. Qunnect provided the hardware while Cisco supplied the software needed to manage the system. The companies said the experiment addressed several obstacles that typically arise when deploying quantum systems in existing data‑center environments.

Quantum computers rely on quantum physics to perform calculations far beyond the reach of classical machines. Many current systems require extensive cryogenic cooling, which limits where they can be installed. Qunnect’s approach reduces this requirement by centralizing cooling at a single hub while allowing connected data centers to operate at room temperature. This design aims to make quantum networking more practical for urban deployments.

Stabilizing Quantum Signals in Noisy Environments

Quantum networks are highly sensitive to environmental disturbances, including vibration and temperature changes. Cisco and Qunnect reported that the startup’s automatic polarization controllers helped maintain signal stability across the fiber route. These devices compensate for distortions introduced by patch panels, cable bends and other irregularities common in data‑center infrastructure. Qunnect CEO Noel Goddard said the technology corrects for “real‑world problems” that typically disrupt quantum communication.

The companies emphasized that the test demonstrates how quantum links can operate reliably over long distances in complex environments. Data centers often contain tens of kilometers of fiber arranged in ways that introduce unpredictable interference. Maintaining quantum coherence under such conditions is a major technical challenge. The experiment suggests that these obstacles can be managed with the right hardware and control systems.

Toward Quantum Data Centers and Future Applications

Cisco Research vice president Ramana Kompella described the experiment as foundational for connecting quantum computers within data centers. He said the long‑term goal is to link multiple quantum facilities into a broader quantum internet. In the near term, practical quantum networks could support applications such as high‑speed financial trading. A technique known as quantum teleportation allows physically separated computers to share information instantaneously rather than waiting for signals to travel at the speed of light.

Kompella noted that trading systems separated by several kilometers could coordinate decisions without latency constraints. Quantum entanglement networks may offer advantages in scenarios where even millisecond delays matter. The companies believe that early demonstrations like this one will help identify realistic use cases for quantum communication. Their work contributes to a growing effort to integrate quantum technologies into existing digital infrastructure.

English summary

Quantum networking research has accelerated in recent years as governments and companies explore secure communication methods resistant to interception. Several national programs, including those in the United States, Europe and China, are investing heavily in quantum‑safe infrastructure. New York has become a notable testing ground due to its dense fiber networks and concentration of financial institutions. Experiments like the Cisco‑Qunnect link highlight how quantum technologies may gradually transition from laboratory prototypes to operational systems.