Japan Operationalizes First Full-Stack Neutral-Atom Quantum Computer “Shunkai”

The Institute for Molecular Science (IMS), part of Japan’s National Institutes of Natural Sciences (NINS), has announced that Japan’s first full-stack neutral-atom quantum computer, named “Shunkai” (春海), is now operational. Led by Project Manager Professor Kenji Ohmori under Goal 6 of the Japanese Cabinet Office / JST Moonshot Research and Development Program, the platform was built through a industry-academia consortium partnering with Hitachi, Ltd. for the software stack and Infleqtion, Inc. for the Quantum Processing Unit (QPU) hardware stack.

Full-Stack Integration and Optical Tweezer Control

The “Shunkai” system is named after Harumi (Shunkai) Shibukawa, the Edo-period astronomer who designed Japan’s first indigenous calendar based on celestial calculations. The full-stack platform integrates user-level software directly down to physical laser control and readout systems:

• Optical Tweezer Qubit Trapping: Single neutral atoms are trapped in a two-dimensional grid using optical tweezers created by tightly focused laser beams through high-NA objective lenses. Quantum logic gates are driven via targeted microwave and laser pulses, with individual readout executed via high-resolution fluorescence cameras.
• Room-Temperature Reconfiguration: Operating without cryogenic dilution refrigerators, the platform leverages dynamic atom transport to physically move qubits during runtime, enabling all-to-all connectivity and reconfigurable circuit topologies.
• Consortium Ecosystem: Hardware component integration and QPU packaging were developed in partnership with Infleqtion, while Hitachi engineered the underlying system orchestration and compiler software stack.