Networking technology giant Cisco Systems Inc. today introduced a new networking switch for quantum systems that routes quantum information between computers while preserving quantum state. 

The Cisco Universal Quantum Switch, a working prototype, is the company’s latest proof of concept aimed at pushing quantum systems closer to real-world practical use. 

Researchers and enterprises already use quantum computers as complementary co-processors to solve specific, mathematically complex problems that are effectively out of reach for classical supercomputers. This is either because they cannot solve them at all or because doing so would take too long to be useful.  

Enterprises are most interested in optimization, molecular simulation for materials science and drug discovery, and quantum-safe cryptography, while researchers are focused more on physics, simulation and new quantum algorithms. 

One of the biggest problems facing quantum computing is scale. To reach powerful enough quantum computers, the industry needs to hit millions of qubits, the fundamental unit of quantum information. Current quantum computers are in the hundreds to low thousands of qubits, and roadmaps point toward the low tens of thousands in the next few years, but practical real-world gains will require systems far beyond that. 

There are two broad ways to reach the practical quantum era: build bigger, more powerful quantum computers, or connect multiple quantum computers together the way classical computers are connected in data centers to behave like a single unified system. Cisco’s innovation does the latter. 

Making quantum networking universal 

It also adds several critical features that make it possible to interconnect systems from multiple vendors without specialized hardware. The switch operates at room temperature and over telecom fiber, and includes a Cisco-patented conversion system that translates between different encoding modalities used by different quantum technologies at input and output. 

That means if two different quantum computers are built by two different companies, they can still talk to each other through the switch. It will translate for them. 

“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,” said Vijoy Pandey, senior vice president and general manager of Outshift, Cisco’s emerging technologies and incubation group. “While this is a significant achievement, it’s just the beginning.” 

The switch is designed to work with major light encoding modalities, including polarization, time-bin, frequency-bin and path encoding. Different quantum systems package information into photons in different ways, so a universal switch has to do more than pass traffic; it has to translate the format without breaking the message. 

Cisco said it has so far validated the system with polarization, which uses the orientation of photons to carry information. A popular example of polarization is used in sunglasses to reduce glare. Support for time-bin and frequency-bin is planned. 

That universality also matters because the quantum industry is still moving in multiple directions at once. Vendors are building different types of quantum systems, and no one yet knows which hardware approach, encoding method or broader ecosystem will emerge as dominant. 

Building around a single modality risks leaving a data center or lab tied to expensive hardware that may not age well. Cisco hopes its switch will let enterprise and research facilities mix boutique and off-the-shelf hardware, with the switch handling the translation in the middle so the network can scale without forcing every system to speak the same native language. 

The longer vision for quantum 

Outside the data center, Cisco said, the current reach is up to 100 kilometers, though the company argued that distance will become less of a limiting factor over time. 

Cisco was also clear that this is not a commercial product yet. The Universal Quantum Switch is a working research prototype and still needs to validate key inventions around conversion and quantum-state preservation before moving further toward commercialization. 

The long-term plan is to build out the networking layer, its hardware, software and protocol for quantum and let it become the stack that applications can rest on as a foundation. As quantum computing reaches practical stability in the enterprise networking at scale is Cisco’s vision of that future. The next one or two years will become the proving ground across hardware and software, the company said as plans come to fruition.

The company is also advancing that vision through partnerships with IBM Corp., Qunnect Inc., Atom Computing Inc. and other industry players. 

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