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Cisco positions quantum networking as the path to scale, aiming to create a heterogeneous compute fabric
Although quantum computing is not yet a mainstream technology, there’s already a clear constraint. Current quantum computers don’t generate enough qubits to address the class of complex problems quantum computing is designed to solve. Cisco is getting ahead of this future constraint with a new switch the company is positioning as capable of connecting different quantum computers into a cohesive whole, aggregating qubit resources and enabling distributed execution.
This week the company announced the Cisco Universal Quantum Switch. The underlying idea is that some of the most difficult problems in finance, logistics, pharmaceutical discovery, materials science and weather prediction require thousands to millions of qubits to solve. Today, quantum computers can generate hundreds to more than a thousand qubits; Cisco partners Atom Computing and IBM, for instance, have both passed the 1,000-qubit mark in specific computers.
One option is to scale up by building increasingly large quantum computers, and major players in the space are pursuing that goal. The other option would be to follow a cloud computing (and AI computing) scale-out paradigm by connecting distributed quantum computers to aggregate capabilities. Cisco is betting on scale-out, a scaling problem best addressed at the network layer, as the most ready path to real-world impact.
“Our focus at Cisco is to build that quantum network,” Vijoy Pandey, general manager and senior vice president of R&D and incubation arm Outshift by Cisco, said this week in a briefing. In May last year the company debuted its Quantum Network Entanglement Chip which functions at room temperature, operates at standard telecom wavelengths and consumes less than 1 mW of power. These same structural benefits are pulled forward into the Universal Quantum Switch. While this technology is still pre-commercial, Cisco’s approach to quantum networking technologies could be integrated into existing infrastructure.
Applicability to existing network infrastructure is key, particularly given alignment with existing fiber infrastructure and telecom wavelengths. This lowers the barrier to integration with existing carrier networks. The nature of quantum computing is such that a major breakthrough could prompt rapid, global diffusion. In that scenario, advantage would likely accrue to service providers with a quantum-ready network infrastructure.
Cisco stressed the universality of its quantum switch design. As various companies, governments and research institutions pursue quantum computing, a number of types of computers (superconducting, trapped ion, photonics and neutral atoms) have emerged. There are also different encoding modalities (polarization, time-bin, frequency-bin and path) with different entanglement schemes built on top of them.
Cisco Head of Quantum Research Reza Nejabati explained that the ability to switch between types of quantum computers using different modalities is key to driving scale. Direct connectivity between quantum computers “just doesn’t scale out and you cannot manage that,” he said.
The long-term vision is of quantum data centers containing all manner of quantum computers connected together, then joining those quantum data centers into what acts like a heterogeneous, distributed quantum system coordinated through a network fabric.
Company Chairman and CEO Chuck Robbins, writing on LinkedIn, said, “For more than 40 years, Cisco has built the critical infrastructure connecting the world. Today, we’ve reached the next major milestone on that journey…Built for interoperability, speed and real-world environments, the Universal Quantum Switch is a major step toward building the foundation for the quantum internet.”
Cisco is signaling that it sees control of the interconnect layer as strategically valuable in quantum as it has been in classical networking.
