IBM and Cisco are developing the groundwork for networked distributed quantum computing. The companies aim to demonstrate a proof-of-concept in 2030, in which multiple large-scale quantum computers reinforce each other.
Connecting quantum computers requires complex technology. Qubits from different quantum computers must be entangled while they are in separate cryogenic environments. IBM will build a Quantum Networking Unit (QNU) for this purpose. This unit acts as an interface for the Quantum Processing Unit (QPU) and converts stationary quantum information into “flying” quantum information.
Cisco is developing a quantum network vision for data centers that distributes entanglement between QNUs. The company is developing a software protocol that dynamically reconfigures networks to distribute entanglement when partial calculations are complete. Microwave-optical transducers should enable the transport of quantum information over longer distances.
In collaboration with Fermi National Accelerator Laboratory through the Superconducting Quantum Materials and Systems Center, IBM plans to demonstrate multiple interconnected QPUs over the next three years.
Scaling up requires networks
Quantum computing is on the cusp of a new phase. IBM has plans to deliver large-scale, fault-tolerant quantum computers before the end of this decade. However, a single quantum computer is not sufficient for the most complex applications. Jay Gambetta, Director of IBM Research and IBM Fellow, says: “By working with Cisco to explore how to link multiple quantum computers like these together into a distributed network, we will pursue how to further scale quantum’s computational power.”
IBM and Cisco aim to demonstrate a proof-of-concept within five years. This network will connect separate quantum computers so that they can calculate together with tens of thousands to hundreds of thousands of qubits. The computing power could then potentially reach trillions of quantum gates, the fundamental operations needed for breakthroughs in optimization, materials design, and drug development.
The road to a quantum internet
The collaboration lays the foundation for a quantum internet that could become a reality by 2040. Such a network would connect quantum computers, quantum sensors, and quantum communication over distances. Vijoy Pandey, GM/SVP at Outshift by Cisco, states: “IBM is building quantum computers 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.”
The companies also want to jointly fund academic research and projects to advance the broader quantum ecosystem. IBM and Cisco are already collaborating with research institutions and national laboratories.