Key Points
- Cisco's quantum switch routes quantum data across different systems without destroying it
- Device operates at room temperature on existing telecom fibre infrastructure
- Prototype demonstrated less than 4 per cent degradation in quantum state fidelity
Cisco has announced a research prototype quantum switch capable of routing quantum information between incompatible systems without destroying the data, a technical barrier that has long hindered efforts to build scalable quantum networks.
The Cisco Universal Quantum Switch, announced on Thursday, can accept quantum signals encoded in different formats and translate them into a common language for routing. The device operates at room temperature on existing telecom fibre, according to the company.
Quantum computers, which process information fundamentally differently from classical machines, encode data using various methods. Until now, no switch could accept and translate between these encoding formats while preserving the fragile quantum information.
Why quantum networking matters
Current quantum computers operate with hundreds of qubits, the basic units of quantum information. Real-world applications in sectors such as healthcare, financial services and aerospace would require millions of qubits to deliver meaningful results.
The American networking technology giant believes networking multiple quantum systems together is essential to bridging this gap. The approach mirrors how classical computer networks evolved; the internet became possible because switches could connect countless endpoints through shared infrastructure rather than direct cables between each device.
“Reaching this milestone is a pivotal moment for our quantum programme and a testament to the transformative potential of quantum networking,” said Vijoy Pandey, Senior Vice President and General Manager of Outshift, Cisco’s Emerging Technologies and Incubation Group.
“We’ve long recognised 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,” Pandey added.
How the switch works
At the heart of the device is a Cisco-patented conversion engine. When two quantum computers need to share information, the switch accepts the signal in whatever encoding format it arrives, translates it for routing, and delivers it in the format the receiving system requires.
The output format can match the input or be entirely different. This enables the switch to connect quantum systems from different vendors that were never designed to communicate with each other, according to the San Jose headquartered firm.
The switch is designed to support four major quantum encoding methods used to carry information. Polarisation encoding uses the orientation of light waves. Time-bin encoding relies on the timing of light pulses. Frequency-bin encoding uses the colour or frequency of light. Path encoding uses the physical or spatial route taken by the signal.
Cisco stated that the switch has been experimentally validated with polarisation encoding to date. Support for time-bin and frequency-bin formats is built into the design and represents the next phase of validation.
Test results from prototype
Cisco researchers tested the switch using the company’s own entanglement source and single-photon detectors. Entanglement is a quantum phenomenon where particles become linked so that measuring one instantly affects the other, regardless of distance.
The experiments demonstrated that quantum information could be routed and converted quickly without being destroyed, according to the company. Key findings from the tests showed less than 4 per cent degradation in quantum state fidelity, the measure of how accurately quantum information is preserved.
The switch achieved sub-nanosecond electro-optic switching, reconfiguring connections in as little as 1 nanosecond. The device consumed less than 1 milliwatt of power during operation.
Unlike many quantum hardware components that require cooling to temperatures near absolute zero, the Universal Quantum Switch operates at room temperature. This eliminates the need for specialised cooling infrastructure, reducing deployment complexity and cost, Cisco stated.
The switch operates at standard telecom frequencies over the same fibre that carries internet traffic today. This means organisations would not need to deploy specialised equipment to use the technology.
The company claims the device allows organisations to avoid being locked into a single vendor for quantum systems. Different manufacturers’ quantum devices could potentially interoperate through the switch.
Broader quantum portfolio
The Universal Quantum Switch is one component of Cisco’s broader quantum networking development programme. The portfolio includes a quantum network entanglement chip that generates the entangled photons quantum networks use to transmit information.
The company has also developed what it describes as an industry-first network-aware Quantum Compiler. This software orchestrates how quantum algorithms are distributed and executed across multiple quantum processors.
All three technologies were developed at Cisco’s dedicated quantum laboratories in Santa Monica, California. The company is also pursuing collaborations with IBM, Qunnect and Atom Computing as part of its quantum networking efforts.
Your Questions, Answered
What does the Cisco Universal Quantum Switch do?
The switch routes quantum information between quantum systems that use different encoding formats. It translates signals into a common language for routing and delivers them in the format the receiving system needs, without destroying the quantum data.
Does the Cisco quantum switch require special cooling?
No. Unlike many quantum hardware components that need cooling to near absolute zero, the Universal Quantum Switch operates at room temperature. This reduces deployment complexity and infrastructure costs.
What infrastructure does the quantum switch need?
The switch operates at standard telecom frequencies over existing fibre optic cables that carry internet traffic today. According to Cisco, no specialised equipment is required.
Has the Cisco quantum switch been tested?
Yes. Cisco researchers tested the prototype using the company's entanglement source and single-photon detectors. Tests showed less than 4 per cent degradation in quantum state fidelity and sub-nanosecond switching speeds.
