Cisco introduces quantum switch for quantum computers

Cisco has unveiled the Universal Quantum Switch, a functional research prototype for connecting quantum computers. It is intended to convert and transmit the differently encoded information from heterogeneous quantum computers. Cisco demonstrated this in a Proof of Concept. With this, Cisco aims to overcome a key hurdle in quantum computing: scaling beyond the limits of individual, currently limited quantum systems.

Transferring quantum information without loss

According to Cisco, the switch operates at room temperature and uses existing optical fibers to create a coherent quantum network. An integrated conversion engine converts incoming signals into a common modality – regardless of polarization, time, frequency, or spatial path. Without measuring or altering the quantum state, the switch routes information via entangled photons, preserving their quantum state. This is crucial because classical switches would destroy the quantum information upon readout.

In the Proof of Concept, the switch transmitted stably with a power loss of no more than 4 percent and switched in the sub-nanosecond range, while maintaining entanglement quality. For context: The Proof of Concept has so far only validated polarization encoding; support for time and frequency encoding is planned in the design and will be experimentally confirmed in further steps. This is a prerequisite for networked quantum computers to operate as a single system.

Hardware compatibility and scaling

The Universal Quantum Switch supports various qubit technologies, including ion traps, photons, or superconducting qubits. This paves the way for collaboration with partners such as IBM and Atom Computing. Vijoy Pandey, SVP and General Manager of Outshift at Cisco, emphasizes: “Interconnectivity is key to scalability. Current quantum computers will grow to 1,000 to a few tens of thousands of qubits in the next three years – but applications in healthcare or aerospace will require millions.”

The switch is part of a comprehensive Cisco portfolio, which also includes a quantum chip for entangled photons and a network-oriented Quantum Compiler. The developments originate from the quantum lab in Santa Monica; Cisco is advancing them together with IBM, Qunnect, and Atom Computing. More information on this and the Universal Quantum Switch can be found in Cisco's announcement.

(mki)