Optical quantum computing at room temp: NTT-OptQC deal

• Optical quantum computing partnership between NTT and OptQC targets one million qubits by 2030 without cryogenic cooling, consuming 1/10 to 1/100 the energy of competing methods
• Approach operates at normal temperature and pressure, potentially enabling deployment in standard data centres rather than specialised facilities

Optical quantum computing operating at room temperature could provide Japan an alternative path in the global quantum race, as NTT Corporation and OptQC signed a collaboration agreement targeting one million qubits by 2030 without the extreme cooling requirements that constrain competing technologies.

The November 18 announcement at NTT’s R&D Forum in Tokyo positions Japan’s government-designated “first year of quantum industrialisation” with a fundamentally different technological approach: using light-based qubits instead of superconducting circuits or trapped ions that require temperatures approaching absolute zero.

NTT President and CEO Akira Shimada and OptQC Representative Director and CEO Hiroshi Takase presented materials showing optical methods require only hundreds of watts of power at normal temperature and pressure, compared to superconducting systems consuming 25 kilowatts with cryogenic vacuum requirements, neutral atom systems needing 7 kilowatts, or ion trap methods requiring 2 kilowatts.

“The optical approach enables scalable and sustainable expansion of qubit counts needed for general-purpose quantum computing, requiring only 1/10 to 1/100 the energy of other methods,” according to presentation materials from NTT.

The Roadmap: From Hundreds to 100 million qubits

The collaboration establishes specific milestones allowing industry observers to track progress. As of 2025, quantum systems worldwide remain at hundreds to thousands of qubits. NTT and OptQC target 10,000 qubits in Japan by 2027, one million qubits by 2030, and materials indicate ambitions to “ultimately reach 100 million qubits ahead of others.”

For context, IBM’s quantum roadmap aims for 100,000 qubits by 2033. The latest superconducting quantum processors reached 1,121 qubits in 2023. The jump to one million qubits by 2030 represents exponential scaling that would leapfrog current leaders if achieved on schedule—and raises questions about feasibility.

The companies position one million qubits as the threshold for “general-purpose applications with major societal impact,” distinguishing research tools from practical commercial infrastructure.

Press materials outlined applications by qubit scale: 100-1,000 qubits handle research simulations, 10,000-100,000 qubits address specialised problems like quantum chemistry and optimisation, while 1-100 million qubits enable complex applications including drug discovery, cryptography, and climate modelling.

Calculation time examples provided by the companies illustrate potential impact: drug discovery requiring “years close to infinite” on conventional computers could be completed in 12 days with 100 million qubits. Fertiliser production from nitrogen in air—solving global food challenges—would take “10 trillion × 1 trillion years” conventionally, but four days with one million qubits.

How optical differs: Multiplexing instead of cooling

The quantum computing industry has largely converged around three main approaches—superconducting circuits, trapped ions, and neutral atoms—all requiring extreme operating conditions.

Superconducting methods need temperatures near absolute zero (-273°C) and large-scale cooling systems. Trapped ions require cryogenic vacuum and complex ion control equipment. Neutral atoms demand vacuum conditions with colossal cooling infrastructure.

Optical quantum computing operates on fundamentally different physics, leveraging techniques NTT developed over decades in optical communications. Light-based qubits enable spatial multiplexing (multiple light paths simultaneously), time multiplexing (different time slots for information), and wavelength multiplexing (different colours of light carrying separate qubits).

These multiplexing capabilities theoretically enable “exceptional scalability” with potential to increase qubit counts without proportional infrastructure or power increasesaccording to presentation materials.

The question is whether this theoretical advantage can overcome the accumulated lead of established approaches that have demonstrated quantum capabilities and attracted billions in investment.

NTT’s optical technology foundation

NTT’s optical communications research dates to the 1990s, with wavelength multiplexing development in 1990, optical amplification in 2013, and photonics-electronics convergence devices targeted for 2028.

The company demonstrated quantum light sources in 2024 and, with OptQC and RIKEN, “realised an internet-accessible photonic quantum computer in 2024,” according to materials.

The collaboration divides responsibilities strategically: NTT contributes optical communication technologies, including quantum light sources, advanced optical amplification and modulation, and wavelength division multiplexing.

OptQC brings optical quantum computer development technologies and operational systems. Four focus areas define the partnership: multiplexing and error correction technologies, use case and algorithm development, supply chain building, and practical deployment strategies.

Regional context and timeline

Japan’s government designated 2025 as the “first year of quantum industrialisation,” signalling national commitment with funding directed toward quantum technology development. For Asia-Pacific countries, NTT’s partnership offers potential alternatives to US or Chinese quantum computing advances, particularly as room-temperature operation could enable deployment in regions with varying power infrastructure.

China has invested heavily in quantum computing with contested claims of quantum supremacy. U.S. companies, including IBM, Google, IonQ, and Rigetti, lead established approaches with transparent roadmaps.

The partnership’s phased approach suggests specialised applications in quantum chemistry and optimisation for research institutions near-term (2025-2027), expanding to industrial applications in pharmaceuticals and materials science medium-term (2027-2030), and transformative applications in drug discovery and climate modelling long-term (2030+) at one million+ qubits.

With US$3 billion in annual R&D investment—30% of NTT’s total profit—the company has committed substantial resources. The five-year timeline with specific milestones means progress will become measurable by 2027’s 10,000-qubit target and 2030’s one million-qubit goal.

Want to experience the full spectrum of enterprise technology innovation? Join TechEx in Amsterdam, California, and London. Covering AI, Big Data, Cyber Security, IoT, Digital Transformation, Intelligent Automation, Edge Computing, and Data Centres, TechEx brings together global leaders to share real-world use cases and in-depth insights. Click here for more information.