Japan just flipped the switch on a machine that could reshape how the world thinks about quantum computing’s path to commercial reality. Researchers at the Institute for Molecular Science (IMS) activated Shunkai on August 24, marking the country’s first operational full-stack neutral-atom quantum computer. The system launches with roughly 50 qubits, but its architects have already mapped a route toward 500 qubits and beyond. Chemist and IMS professor Kenji Ohmori, PhD, led the research team behind the build, working within Japan’s ambitious Quantum Moonshot program. At the heart of Shunkai sits a quantum processing unit supplied by Infleqtion, a Colorado-based quantum technology company. The pairing signals something bigger than a single lab’s achievement; it shows how international partnerships are now driving Japan’s national quantum strategy.

Shunkai Marks Japan’s First Full-Stack Quantum Machine

Shunkai isn’t simply a prototype confined to a lab bench; it’s a working, full-stack system that is now operational and designed to run quantum computations as the project advances. The National Institutes of Natural Sciences, which oversees IMS, announced the launch as Japan’s first full-stack neutral-atom quantum computer. Ohmori’s team designed the machine to scale, starting at approximately 50 qubits with a clear technical pathway to approximately 500. That scaling ambition matters because quantum computers face significant challenges in increasing qubit numbers while maintaining the control and fidelity required for useful quantum computation. Shunkai’s neutral-atom design offers potential advantages in scalability and flexible qubit configuration, which are among the reasons neutral-atom systems are attracting attention from industry, academia and governments worldwide. Consequently, the machine’s early operation will provide an important platform for researchers evaluating how neutral-atom architecture can advance toward larger-scale quantum computing.

Infleqtion’s Role in Japan’s Quantum Moonshot

Infleqtion didn’t just contribute a piece of hardware, it became the sole foreign quantum partner selected by the Japan Science and Technology Agency for the Quantum Moonshot program. That distinction carries weight in the project because Infleqtion contributed its quantum processing unit in collaboration with the Ohmori group at IMS. The Quantum Moonshot program itself targets a far bigger prize: a fault-tolerant, universal quantum computer by 2050, a goal that Japan is pursuing through multiple hardware, software and networking research projects.

Infleqtion CTO Pranav Gokhale framed the launch in stark terms. “This milestone marks a pivotal moment for Japan’s quantum ambitions as well as Infleqtion’s role in advancing production-ready quantum platforms at scale,” Gokhale said. His comment reflects Infleqtion’s focus on developing scalable neutral-atom quantum platforms, while Shunkai provides an operational full-stack system for the Ohmori Moonshot project. For Infleqtion, Shunkai’s activation represents a significant technology milestone, demonstrating its QPU’s role in an operational full-stack quantum computing platform.

Why Neutral-Atom Qubits Are Different

Neutral-atom quantum computers rely on individual atoms as their qubits, the fundamental units of quantum information that make quantum computing possible in the first place. Unlike superconducting qubits, which need dilution refrigerators cooled to near absolute zero, neutral atoms can operate without the large-scale refrigeration infrastructure required by superconducting systems. Scientists trap and manipulate these atoms using precisely controlled laser light, a technique that lets them position and control qubits with high precision.

This laser-based control also allows researchers to move atoms and flexibly configure qubits for different computational tasks, rather than relying on a permanently fixed arrangement. That flexibility is a major reason neutral-atom quantum computing is attracting attention as a promising route toward larger quantum computers. Because these atoms can be arranged in large arrays while researchers maintain control over their quantum states, engineers see potential for scaling the number of qubits while continuing to address the control and fidelity challenges that accompany larger systems.

The Next Phase: Scaling Toward 10,000 Qubits

Shunkai’s current form is a starting point, not a finish line, for the broader Ohmori Moonshot project. A new phase of that project began in April 2026, and it’s focused squarely on improving the system’s integration, stability and scalability over time. The target is striking: a high-performance, fault-tolerant neutral-atom quantum computer with as many as 10,000 physical qubits and quantum error detection and correction capabilities. Gokhale described the significance of reaching this operational stage in direct terms. “Bringing a full-stack quantum system into production operation is a meaningful step toward fault-tolerant quantum computing that also serves as strong validation of neutral-atom architecture,” he said in a press release. Still, hitting a qubit count in the thousands won’t automatically deliver fault tolerance, and the research team knows it. Instead, the harder work lies in building reliable methods to detect and correct the errors that inevitably arise in quantum calculations. 

Error Correction Remains the Real Challenge

Quantum systems are notoriously sensitive to their surroundings, and disturbances such as heat, vibration or stray light can affect the accuracy of a calculation. Because errors can accumulate as a computation runs, they can corrupt results if they are not detected and corrected. Error correction addresses this problem by encoding a unit of quantum information across multiple physical qubits, creating redundancy that can protect the information against certain physical errors. This approach, however, demands significantly more hardware than the number of logical qubits might suggest, which is part of why fault-tolerant quantum computing requires large numbers of physical qubits. Building that redundancy into a neutral-atom system at scale is precisely one of the technical challenges the next phase of the Ohmori Moonshot project is designed to address. Meanwhile, the operation of Shunkai will provide researchers with an important platform for developing and demonstrating quantum error-correction techniques. 

Opening The Door To Outside Researchers

The team behind Shunkai doesn’t intend to keep the machine locked inside IMS. Plans are already in motion to make the technology partially available to external users from both academia and industry, turning a single research machine into a platform for collaborative development. That kind of access could support the search for practical quantum applications while giving outside teams a real system to test and develop quantum error-correction techniques on, rather than relying purely on simulation.

Ohmori has been direct about why this matters to him personally and to Japan’s broader quantum strategy. He said opening Shunkai to outside researchers and companies could help advance error-correction technologies and practical quantum applications while creating wider benefits across industry, academia and government worldwide. “I think it is extremely significant that now we have developed Japan’s first full-stack quantum computer in this cutting-edge modality and started its operation,” Ohmori said in a statement. That sentiment captures the stakes: Shunkai is both an operational research platform and a foundation for broader work toward practical quantum computing in Japan.

Building a Hybrid Quantum-GPU Future

Looking further ahead, the team plans to integrate Shunkai with IMS’s existing shared supercomputer facility, creating a hybrid quantum-GPU computing center. That combination reflects an increasingly important direction in quantum computing: quantum processors are expected to work alongside classical computing resources rather than replace them outright. For Japan, this hybrid approach also offers a practical framework for combining quantum hardware with existing classical computing infrastructure. Additionally, tying Shunkai into an existing supercomputer facility would give researchers access to complementary classical computing resources needed to support larger-scale quantum experiments. This kind of integration is an important part of the infrastructure planning surrounding the Ohmori Moonshot project. As the Quantum Moonshot program pushes toward its 2050 target, Shunkai’s hybrid future may end up being just as important as the qubit count itself. 

What Comes Next for Japan’s Quantum Ambitions

Shunkai’s activation puts Japan among the countries operating full-stack quantum hardware built on neutral-atom architecture. The partnership with Infleqtion also demonstrates how this project combines Japanese research leadership with international quantum technology expertise. Researchers and policymakers watching the neutral-atom quantum computing space now have an operational full-stack system to evaluate alongside other research platforms and technology roadmaps.

With qubit counts set to climb from approximately 50 toward approximately 500, and with a longer-term goal of reaching up to 10,000 physical qubits with quantum error detection and correction capabilities, Shunkai’s next few years of operation will provide valuable data on how neutral-atom architecture performs as the system scales. Every milestone along that path, from stability improvements to progress in error correction, will help inform how researchers approach scaling decisions. For now, Japan has its machine running, its roadmap set, and a partner in Infleqtion contributing its quantum processing unit as the Ohmori Moonshot project works to advance neutral-atom quantum computing toward larger-scale and fault-tolerant systems.