If you’ve been following Qunnect’s work the past few months, you’ve likely seen a theme: proving entanglement-based quantum networks can operate beyond a lab and in the real world.

From day one, we’ve been focused on building quantum networks that function on deployed telecom fiber in real cities. That’s why our Carina hardware was designed to produce high-quality, atom-based entangled photons engineered for stability in real-world environments. We’ve now demonstrated the hardware across multiple cities.

One of the challenges in scaling real-world quantum networks is the practical realization of protocols to route entanglement between network nodes. To do that, you need entanglement “swapping”—essentially, the operation that extends entanglement from two nodes to multiple ones through an intermediate hub. Swapping itself is well-established in quantum science, yet performing it on telecom-compatible infrastructure under real-world constraints has remained rare in the industry. Loss, noise, and hardware complexity make it far more challenging outside of controlled laboratory settings.

That is, until now.

This month, Cisco, the NYU Quantum Institute, and Qunnect demonstrated the first polarization entanglement swapping at telecom wavelengths using fully independent entanglement sources over deployed telecom fiber. The experiment was conducted through a major carrier data-center hub at QTD Systems’ 60 Hudson facility in Manhattan. While entanglement swapping has been achieved in laboratory environments before, doing so at telecom wavelengths, with independent sources, on city-scale deployed fiber using practical, room-temperature hardware marks a new stage of technical maturity for quantum networking.

Why does this matter? Because to truly impact the world, quantum networking needs to go beyond a few deployments to meaningful connectivity at scale. That means working on the networks the world already uses, through the types of hubs where modern connectivity already converges.

It has to operate through today’s data centers.

Using Qunnect’s atom-based entanglement sources, Cisco’s quantum networking software stack, and commercial telecom fiber, we also achieved the highest entanglement-swapping rates reported to date. That performance level is critical for future quantum repeaters and distributed quantum computing architectures.

Achieving this milestone required overcoming two key barriers. First, photons generated by separate entanglement sources need to be indistinguishable when they arrive at the hub. Carina’s atom-based source design tightly controls wavelength, polarization, and spectral properties for high rate, high purity output. Those characteristics are maintained during transmission over telecom fiber by Carina’s instruments that compensate for imperfections in the fiber. Second, detection timing must be extraordinarily precise – down to fractions of a billionth of a second. Historically, this level of performance required cryogenics at every node, but Qunnect eliminated that. This experiment achieved record swapping rates using off-the-shelf, room-temperature detectors at the outer nodes, which dramatically lowers cost and complexity.

Equally important is where the demonstration happened. Using a telecommunications data center as the hub is a major benefit to the network architecture. It means the power, monitoring, security, and operational staffing are already in place, allowing complexity to concentrate at the hub while edge nodes remain simpler. That makes expansion much more practical because you can add nodes without rebuilding the system each time.

Like its digital predecessor, the quantum internet is an evolution of technologies . Like any infrastructure, it will be built incrementally, with technical and operational proofs that reduce operational and cost barriers over time.

Now, with Cisco, NYU and Qunnect working together, we’ve proven that entanglement can be coordinated and scaled through controller-driven workflows over deployed telecom fiber – just like a classical network. From three nodes to three thousand isn’t marketing language; it’s a sign of what’s to come, and the blueprint for how to get there.

In short, the only way to scale… is to swap.

To read the paper that accompanies these results, click here.