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.
| [ IMS Neutral-Atom System Architecture: “Shunkai” ] | ||
|---|---|---|
| Hardware Stack (QPU) | Software & Control Stack | Scale & Roadmap Targets |
| • Neutral Rubidium Atoms | • Hitachi Software Stack | • Phase 1: 50 Physical Qubits |
| • Optical Tweezer Arrays | • Infleqtion QPU Electronics | • Phase 2: 500 Physical Qubits |
| • Room-Temp Qubit Control | • Dynamically Moved Atoms | • 2031 Target: 10k FTQC Qubits |
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.
R&D Roadmap Toward 10,000-Qubit Fault-Tolerant Systems
The operational launch marks the transition into Stage 2 of the Ohmori Moonshot Project (Neutral atom-based fault-tolerant quantum computer), which runs through March 2031:
- Near-Term External Access: Starting with approximately 50 physical qubits, the system will scale to 500 qubits while opening partial cloud access to academic and corporate researchers for algorithm optimization and quantum error correction (QEC) experiments.
- Commercialization Conduit: Academic spin-out Yaqumo Inc. (co-founded by Prof. Ohmori) will drive commercial application development and system deployment across Japanese enterprise sectors.
- HPC-Quantum Hybrid Center: IMS plans to integrate Shunkai with its existing shared supercomputer facilities to establish a regional quantum-GPU hybrid computing hub.
- Long-Term FTQC Goal: By March 2031, the Moonshot team aims to deliver a fault-tolerant quantum computer featuring 10,000 physical qubits with active quantum error detection and correction.
Supported by funding from the Cabinet Office/JST Moonshot R&D Program and the MEXT Quantum Leap Flagship Program (Q-LEAP), Shunkai establishes Japan’s sovereign domestic footprint in neutral-atom quantum processing.
Review official release details on the Institute for Molecular Science here, explore program goals via the JST Moonshot R&D Program Goal 6, inspect research methodologies on Ohmori Group, and examine our previous coverage of IISc and Yaqumo Strategic Coalition for Indo-Japanese Neutral-Atom Quantum Hardware R&D here.
August 24, 2026