Cisco’s Universal Quantum Switch Paves Way for Interconnected Quantum Systems

Cisco  announced the Cisco Universal Quantum Switch, a critical milestone in quantum networking that addresses one of the most fundamental barriers to building a quantum network. As a working research prototype, it is the latest proof point in Cisco’s accelerating full-stack quantum networking program, built on years of foundational research, real-world demonstrations, and a growing ecosystem of strategic collaborations.

Quantum computers encode information in different ways, and until now, no switch could accept and translate between all major encoding modalities without destroying the quantum information in the process. The Cisco Universal Quantum Switch is designed to address this challenge for the first time, routing quantum information while preserving it at room temperature, on existing telecom fiber, with a Cisco-patented conversion engine that translates between encoding modalities at input and output.

“Reaching this milestone is a pivotal moment for our quantum program and a testament to the transformative potential of quantum networking. We’ve long recognized that connecting quantum systems is the key to achieving true scalability, and now we’ve taken a critical step toward making that vision a reality. While this is a significant achievement, it’s just the beginning. The road ahead is long, yet the impact of what we are building—and what is still to come—will be nothing short of profound.”

– Vijoy Pandey, SVP/GM of Outshift, Cisco’s Emerging Technologies and Incubation Group

Cisco Is Building the Network Layer for the Quantum Era

Today’s quantum computers are powerful but limited, operating at hundreds of qubits when real-world applications in healthcare, financial services, and aerospace will need millions to achieve unheard of speeds and technological breakthroughs. Cisco believes networking and connectivity are central to bridging that gap. The quantum future will not be built by any one company or any one technology. It will be built by connecting them all.

Imagine connecting billions of people and tens of billions of devices with direct cables. It would be unmanageable. The internet became possible because classical switches could connect all of those endpoints through a shared, scalable network. The Cisco Universal Quantum Switch does the same thing for quantum. When two quantum computers need to share information, it accepts the signal in whatever modality it arrives, translates it into a common language for routing, and delivers it in the format the receiving system needs, without losing any quantum information along the way.

This is made possible by a Cisco-patented conversion engine at the heart of the quantum switch. The output modality can match the input or be an entirely different one, enabling the quantum switch to connect and translate between quantum systems that were never designed to talk to each other, a critical capability for building quantum networks that work across different vendors and technologies.

The quantum switch is designed to support all major quantum encoding modalities used to carry information:

• Polarization (the orientation of light waves)
• Time-Bin (the timing of light pulses)
• Frequency-Bin (the color or frequency of light)
• Path (the physical or spatial path)

To date, the quantum switch has been experimentally validated with polarization encoding. Support for time-bin and frequency-bin is built into the design and represents the next step in Cisco’s ongoing validation process.

Proof-of-Concept Experiments and Results

The Cisco Universal Quantum Switch was tested by Cisco researchers using Cisco’s own entanglement source and single-photon detectors. In these experiments, the switch demonstrated that quantum information can be routed and converted across systems quickly, accurately, and efficiently, without destroying it in the process.

Key findings include:

• Quantum information preserved through conversion: Average of less than or equal to 4% degradation in quantum state fidelity and entanglement, maintaining the coherence that quantum networks require to function.
• Switching at the speed quantum networks demand: Nano-second electro-optic switching, reconfiguring connections in as little as 1 nanosecond
• Energy efficient: Consumes less than 1 watt of power

Cisco’s Vision for What Comes Next

For more than four decades, Cisco has built infrastructure that connects the world. The Cisco Universal Quantum Switch is the latest milestone in that journey, reflecting Cisco’s conviction that the road to practical quantum computing will be built via a distributed network of interconnected quantum devices in a matter of years, not decades.