NTT and OptQC partner to advance optical quantum computers — Towards one million qubits

On November 18, NTT and OptQC signed a collaboration agreement to realize scalable and highly reliable optical quantum computers. President and CEO Akira Shimada of NTT and Representative Director and CEO Kan Takase of OptQC stated that achieving practical-level performance requires generating between one million and 100 million qubits. As a first step, they aim to achieve scalability at the one million qubit level and to establish error correction technology for ensuring computational reliability by 2030.

Current quantum computers are still small in scale, and qubits are extremely sensitive. Even slight noise or fluctuations can disturb quantum states, leading to incorrect results.

For practical use, generating at least one million qubits and stably generating and controlling thousands of logical qubits using error correction technology is required.

Various approaches to creating qubits, such as superconducting, neutral atom, and ion trap methods, are being researched and developed worldwide. Most of these create qubits in special environments like low temperatures or vacuums, and require large cooling systems, large-scale optical control systems, or ion control devices to operate. This presents significant technical hurdles for practical implementation.

In contrast, optical quantum computers that leverage the properties of light offer advantages over other approaches, including low power consumption, operation at room temperature and normal pressure, and the ability to function without external equipment.

Moreover, various technologies and equipment that NTT has developed for practical optical fiber communications can be utilized, reducing both development costs and timelines.

Under the IOWN initiative, NTT has been conducting research and development on optical amplification technology, optical multiplexing technology, and error correction technology to achieve high-speed, large-capacity optical communications, all of which can also be applied to quantum light sources. For example, by creating a quantum light source using optical amplification technology, NTT became the first in the world to achieve quantum generation more than 1,000 times faster than conventional methods.

On the other hand, OptQC is a startup company, founded in September 2024, which builds upon 25 years of basic research on optical quantum computers at the University of Tokyo's Furusawa Laboratory (Professor Akira Furusawa).

The company has accomplished various fundamental technologies, including the world's first realization of a new type of optical quantum computer operating at room temperature and normal pressure, ultra-broadband quantum measurement using optical amplifiers, and qubit generation for error correction.

Currently, OptQC is working on developing a 10,000-qubit optical quantum computer in a NEDO project. The two companies aim to achieve the one million qubit scale, a benchmark for practical use, by 2030. At the one million qubit scale, extremely difficult challenges such as producing fertilizer from atmospheric nitrogen using low energy could be solved in just four days.

Under this collaboration agreement, the two companies will jointly explore the development of multiplexing technology and error correction technology, use case creation and social implementation, in addition to algorithm and software development. In the second year, they will establish a development environment, and in the third year, they will verify use cases.