Cisco, IBM team to build large-scale quantum networks

Cisco and IBM plan to pool their R&D efforts to build a network of large-scale, fault-tolerant quantum computers capable of working together to run computations up to hundreds of thousands of qubits. They aim to demonstrate the first proof-of-concept within five years, though much of this technology has not been developed yet.

As part of the collaboration, the vendors will look to develop quantum hardware and software that could physically link many large-scale, fault-tolerant quantum computers together to form networked distributed quantum computing. Their initial proof-of-concept calls for entangling qubits from multiple separate quantum computers located in distinct cryogenic environments. “Doing so will require the companies to invent new connections, including microwave-optical transducers and a supporting software stack,” the vendors stated.

“Getting quantum computing to useful scale is not just about building bigger individual machines, it is also about connecting them together,” Vijoy Pandey, general manager and senior vice president at Outshift by Cisco, said in a statement. “IBM is building quantum processors with aggressive roadmaps for scale-up, and we are bringing quantum networking that enables scale-out. Together, we are solving this as a complete system problem including the hardware to connect quantum processors, the software to run computations across them, and the networking intelligence that makes it work.”

[[Related: Top quantum breakthroughs of 2025]]

IBM has talked about developing an interface to its quantum computers called a Quantum Networking Unit (QNU), which will allow for microwave-based link research and prototyping. IBM announced this month it is working with the Superconducting Quantum Materials and Systems Center (SQMS) at Fermi National Accelerator Laboratory to entangle two IBM quantum computers in separate cryogenic infrastructures, linked together by a microwave-based quantum network as an interconnected data center. QNU-based systems could be used across potentially multiple quantum computers through a network.

IBM is doing similar work with Cisco.

“To scale beyond linking two quantum computers that are separate but physically close, IBM and Cisco are planning to explore how to transmit qubits over longer distances, such as between buildings or data centers,” the companies stated. “To achieve this, the companies will explore optical-photon and microwave-optical transducer technologies and investigate how they can be incorporated into a quantum network to transfer quantum information as needed.”

Cisco’s quantum network would aim to distribute the entanglements to arbitrary pairs of QNUs on an on-demand basis to drive the quantum information transfer required for a given quantum algorithm or application, the vendors said. “Towards this goal, Cisco is developing a high-speed software protocol framework that can continuously and dynamically reconfigure network paths so entanglements could be distributed to the QNUs when they are done with their partial computations.”

Big Blue and Cisco said they plan to investigate how a network bridge, comprised of novel hardware and open-source software, could use Cisco quantum network nodes to link many IBM QPUs within a data center through its QNU interface. Looking ahead, this approach could be extended to link QPUs across multiple data centers, the vendors said. This would scale a larger quantum network across even larger distances to form the groundwork for a future quantum computing internet.

Building a distributed and scalable quantum computing network will create a pathway towards an exponentially large computational space and allow the expansion of diverse technologies, which could begin to form a future quantum computing internet by the late 2030s, IBM and Cisco stated.

“A quantum computing internet provides a future where many distributed quantum-based technologies, such as quantum computers, quantum sensors, and quantum communications are connected and share information across distances, such as a metro region and eventually at a planetary scale,” the vendors stated.

Recent quantum progress

Both IBM and Cisco have made a number of quantum-related announcements in recent months.

• IBM unveiled its new Nighthawk quantum processor, which will be commercially available by the end of the year. It is built around a new topology that increases the number of couplers, and it has a modular design that will allow it to scale further than IBM’s Heron processor. By the end of 2026, Nighthawk’s new modular architecture and advanced error-correction will allow it to support 7,500 gates — and get to 10,000 gates in 2027 and 15,000 in 2028.
• Cisco’s Quantum Labs designed a software stack that includes three layers: an application layer with a network-aware distributed quantum computing compiler that supports quantum algorithm execution in a networked quantum data center; a control layer with quantum networking protocols and algorithms that support the applications as well as manage the devices (hardware and software) that make up a quantum network through northbound and southbound APIs; and a third layer for device support, consisting of an SDK and APIs to physical devices as well as a library of emulated and simulated ones.
• Cisco unveiled a quantum entanglement chip that generates pairs of entangled photons that can instantly transmit quantum state between each other, regardless of the distance between them. The entanglement chip generates 200 million entangled pairs per second and is designed to work with existing infrastructure, meaning it can send photons over existing fiber, and it operates at standard telecom frequencies, so there’s no need to rip and replace anything to support it, according to Outshift. In addition, because of these properties, customers could deploy gear supporting the chip alongside an existing classical computer infrastructure.

Cisco