Cisco launches Quantum Network Controller to scale distributed networks

Cisco is expanding its quantum networking technology with the introduction of a new Quantum Network Controller, designed to manage distributed quantum networks. The controller coordinates quantum computers, memories, and switches, allowing applications to use the network without understanding each component's intricacies, as explained in a blog post by Vijoy Pandey, senior vice president and general manager of Outshift by Cisco.

The controller addresses the scalability challenge of quantum networks. Previously, networks were built point-to-point, limiting them to a few nodes. The new controller enables every node to connect to every other node through a shared fabric, simplifying the management of entanglement distribution. It also introduces Entanglement-as-a-Service (EaaS), a model that schedules entanglement on demand, similar to how cloud infrastructure manages CPU cycles.

The controller includes a hardware abstraction layer, ensuring compatibility with devices from various vendors. It also monitors link quality statistically and applies predefined corrections, escalating to human intervention only when necessary. The controller reclaims hardware resources immediately after a job ends, ensuring efficient use of the network.

In addition to the controller, Cisco has updated its Network-Aware Quantum Compiler, which plans quantum computations by considering the network's capabilities. This compiler integrates distributed error correction, allowing it to plan for network operations needed to measure seams between surface-code patches on different quantum processing units. The compiler treats the network as part of the compilation process, making partitioning and scheduling decisions based on real models of switches, fiber, and entanglement.