NTT & OptQC to build million-qubit optical quantum computer

NTT has announced a collaboration with OptQC to build a 1-million-qubit optical quantum computer by 2030, using photonic technology which enables operation at room temperature. The initiative will combine resources from both companies and target complex computational challenges relevant to a range of industries.

Optical quantum plans

The planned quantum computer will use light to process information, rather than electrical signals found in conventional systems. This is expected to enhance scalability, reliability, and practicality, while reducing energy requirements. The partnership aims to complete development within five years and address current obstacles in quantum computing, such as noise sensitivity and the need for specialised environments.

The first phase of work will focus on four areas: multiplexing and error correction technologies tailored to optical systems, creating new use cases and software, establishing a supply chain, and fostering social implementation of the technology. The companies aim to reach the qubit scale necessary for commercial quantum computing and ensure stable control and error correction.

Technical approach

Quantum computers are often susceptible to their environment, where minor disturbances can destabilise quantum states and result in errors. Today's quantum computers generally require low temperatures or vacuums, but the optical system being developed by NTT and OptQC is designed to operate at room temperature and atmospheric pressure.

NTT intends to contribute technologies from its Innovative Optical and Wireless Network (IOWN) Initiative, such as quantum light sources, optical multiplexing, and error correction. OptQC has previously developed an optical quantum computer that runs at room temperature and will draw from this experience in the joint project, progressing toward a scalable, commercially viable system.

Sector applications

Potential applications for an optical quantum computer include drug discovery, financial modelling, materials development, and climate prediction. These functions require managing large datasets and complex calculations beyond the reach of classical computing.

The partnership's research will evaluate specific use cases and develop algorithms and supporting software during the initial years. Subsequent phases will involve building a development environment, verifying use cases, and expanding collaboration with additional partners.

Industry milestones

NTT's recent work in optical quantum computing includes research partnerships and the creation of a platform for general-purpose optical quantum computing, carried out with academic and research institutions. In early 2025, NTT, the University of Tokyo, and research bodies developed an optical quantum computing platform capable of calculations using optical pulses with strong quantum properties.

OptQC's ongoing projects include work with the New Energy and Industrial Technology Development Organisation's initiatives to strengthen post-5G communications infrastructure, with a focus on practical implementation of optical quantum devices.

Strategic aims

The companies project a phased approach over five years: conducting technical studies and defining use cases in the first year, developing hardware and a supporting environment in the second, and verifying use cases in the third. The latter stages will be dedicated to scaling and social deployment of the optical quantum computer.