Fujitsu and Japan’s Riken Center for Computational Science have announced the development of a 256-qubit superconducting quantum computer.

The system builds on the 64-qubit quantum computer previously developed and deployed by the two partners at the Riken RQC-Fujitsu Collaboration Center in October 2023.

In a statement, Fujitsu said the new quantum computer incorporates “newly developed high-density implementation techniques.” The system uses a superconducting quantum bit chip with a unique three-dimensional mounting layout that allows qubits to be arranged in four-unit cells.

The 256-qubit machine utilizes the same unit cell design established in its 64-qubit predecessor, which the organizations say demonstrates the scalability of this architectural approach. Additionally, despite the system quadrupling in density, it can still be scaled within the previously developed dilution refrigerator, allowing the 256-qubit machine to operate within the same cooling unit as the 64-qubit system.

Fujitsu and Riken are both part of a consortium of research partners that won an award for the successful development of a high-performance hybrid-quantum computing platform. Received by the consortium in March 2024, the award recognizes its development of a high-performance computing platform that uses Japan’s second domestically made superconducting quantum computer.

The two partners said they will integrate the 256-qubit superconducting quantum computer into their hybrid quantum computing platform.

In addition to developing the 256-qubit supercomputer, both organizations have pledged to continue with their R&D efforts, with the hopes of installing a 1,000-qubit machine at the new Fujitsu Technology Park in 2026.

The installation period of their Collaboration Center has also been extended from March 2025 to March 2029.