Computing equipment in Japan touted as "one of the world's largest quantum computers" will no longer be called such, the Cabinet Office announced on March 22.
The move comes on the heels of criticism from specialists that the equipment -- a quantum neural network developed by Nippon Telegraph and Telephone Corp. (NTT), the National Institute of Informatics (NII) and other bodies -- could not really be called a "quantum computer," after researchers went public with the system's development.
Researchers hope quantum computers will surpass the calculation capabilities of supercomputers. The project to build the quantum neural network was funded through the Cabinet Office's Impulsing Paradigm Change through Disruptive Technologies Program (ImPACT), and its development was overseen by NII emeritus professor Yoshihisa Yamamoto.
The interaction of 2,000 photons to perform calculations was the signature feature of the system, but part of the computer relied on general-purpose integrated circuits.
"It's a new kind of quantum computer," Yamamoto insisted in response to a Mainichi Shimbun request for comment.
However, after hearing the testimony of members of the development team and external experts, Cabinet Office personnel were of the opinion that "there is a possibility the integrated circuits are determining the calculation speed, and it is uncertain if processing performance will really improve." The Cabinet Office then decided at a March 22 ImPACT working group gathering to strip the system of its title of a quantum computer, and Yamamoto reportedly agreed.
A publicity representative from NII disclosed that using the catch phrase "one of the world's largest quantum computers" in the press release about the project was Yamamoto's own personal idea, and commented, "It is not appropriate to call this system a quantum computer."