Japan’s First Atom Quantum Computer Runs on Infleqtion’s QPU

The Institute for Molecular Science said on August 24, 2026 that Shunkai, Japan’s first full-stack neutral-atom quantum computer, is operational. Infleqtion of Louisville, Colorado, listed on the NYSE as INFQ, contributed its quantum processing unit. Hitachi, Ltd. wrote the software, and IMS led the build. The first array uses about 50 qubits.

That split is the story the launch notice buried. Infleqtion is a supplier inside a Japanese national machine, and IMS is the owner of the stack.

IMS Built the Stack, Infleqtion Built the Processor

Professor Kenji Ohmori, professor and chairman at IMS, which sits inside the National Institutes of Natural Sciences, is project manager for the Moonshot work. Assistant Professor Takafumi Tomita is on the IMS team and took the first public photograph of the machine. Infleqtion describes itself as one of the principal investigators on Ohmori’s project, and its release still puts the QPU at the center of the announcement.

IMS’s own notice is blunter about who built what. The institute says it took the lead on the full-stack system, with Hitachi on the software stack and Infleqtion on the QPU stack. A full-stack machine, in IMS’s definition, is the chain that turns a user’s input into drive signals for the device and then into a result, the same idea that sits behind a PC or a supercomputer.

WHO BUILT SHUNKAI

Yaqumo is easy to miss in a vendor headline, and it is the Japanese commercial hook IMS put on the record. Ohmori is a founder and executive advisor there, and IMS says the lab will work with the company on putting the computer to use and on later upgrades. Hitachi’s named performer on the current JST project page is Takashi Takemoto. Infleqtion’s public face on the August launch was Pranav Gokhale, the company’s chief technology officer.

A 50-Qubit Machine Named for an Edo Astronomer

Inside the box, single atoms sit in an array of optical tweezers, which are laser spots focused by an objective lens. Gates run by shining microwaves or laser light on those atoms. A camera reads the answer by watching fluorescence from each atom. IMS says the early machine will use about 50 qubits and then grow to about 500 qubits, a tenfold step, and that parts of the system will be opened to outside users for applications and for error-correction tests.

Tomita named the computer. Shunkai (春海) is another reading of Harumi, the given name of Harumi Shibukawa, an Edo-period astronomer (1603-1867) who built Japan’s first original calendar. Tomita wrote that the path of bodies on the celestial sphere is meant to echo the control of quantum states on the Bloch sphere, the map physicists use for a qubit, and that the name is a nod to precise calculation.

Fifty qubits is a starter array, not a finished national computer. The Moonshot clock behind it is the part that makes the switch-on more than a lab photo, because the same team has already written down the next two scale jumps in public.

Why Japan Is Betting on Room-Temperature Atoms

Neutral-atom machines use one atom as one qubit and run at room temperature, so they do not need the giant refrigerators that superconducting chips demand. IMS lists five traits it thinks can beat the limits of that older approach: room-temperature operation, entanglement between chosen pairs by moving atoms during a run, a layout that can be retuned for each algorithm, a relatively easy path to more qubits, and a long lifetime for the information stored in each atom.

WHAT IMS SAYS THE ATOMS BUY

• No fridge: The qubits run at room temperature, without a cryogenic stack.
• Moving qubits: Atoms can be shifted during a calculation so any pair can be entangled.
• Flexible layout: The array can be reshaped to fit the algorithm in use.
• Headroom: IMS says adding qubits is comparatively straightforward on this hardware.
• Hold time: Each atom is described as storing quantum information for a long lifetime.

Ohmori’s scientific calling card is speed. When Infleqtion joined the program, it said his group had run an ultrafast two-qubit gate between two single atoms and had cut the usual atom-gate time by two orders of magnitude, about 100 times. That is the Japanese research Infleqtion bought into, and it is why a US QPU sitting in an IMS lab is not a random export sale.

Japan is not starting from zero on quantum computers. Superconducting work has had a longer head start, which Ohmori himself notes. Shunkai is the first Japanese full-stack machine in the atom style, and that is a narrower claim than “Japan’s first quantum computer,” which the launch language sometimes invites people to hear.

Moonshot Goal 6 Runs Through March 2031

Shunkai sits under Goal 6 of the Cabinet Office and Japan Science and Technology Agency Moonshot program, which is written as the realization of a fault-tolerant computer by 2050. Ohmori’s first-stage project, “Large-scale and high-coherence fault-tolerant quantum computer with dynamical atom arrays,” carried grant JPMJMS2269. IMS also lists MEXT Quantum Leap Flagship Program funding under JPMXS0118069021. JST’s Moonshot news log recorded on January 9, 2025 that Infleqtion had completed the QPU design.

The second stage, titled Neutral Atom-Based Fault-Tolerant Quantum Computer and numbered JPMJMS256D, began in April 2026. IMS says that run lasts until March 2031. The public target at the end of that stage is a large, high-performance atom machine with 10,000 physical qubits, plus error detection and correction, opened to outside users. From about 50 qubits to 10,000 is a 200-fold jump in the physical array, and it is a goal, not a present count.

JST’s current Ohmori project page sets nearer 2028 and 2030 project milestones that are more modest, and more specific, than the 10,000-qubit line.

THE MOONSHOT CLOCK

1. January 9, 2025: JST records that Infleqtion has completed the QPU design.
2. April 2026: The second Ohmori Moonshot stage begins, aimed at integration, stability, and scale.
3. August 24, 2026: IMS announces that Shunkai is operational at about 50 qubits.
4. By 2028: JST’s page says quantum error correction is shown to work, and outside users inside the Ohmori project run circuits.
5. By 2030: A universal gate set with logical qubits is in place, and users outside the Ohmori project run logical circuits.
6. March 2031: IMS’s end-of-stage goal is 10,000 physical qubits with error detection and correction, open to external users.
7. 2050: Moonshot Goal 6 still names a fault-tolerant universal quantum computer as the national end point.

Those dates are the bet. An operational 50-qubit stack in 2026 is a completed step. Error-corrected logical circuits for people outside Ohmori’s group are still a 2030 line on a government page, and the 10,000-qubit machine is a 2031 line. IMS says the next work is integration, control, longer stable runs, and higher-fidelity gates, which is another way of saying the first machine is a platform to beat on, not a finished product.

Infleqtion Is the Only Foreign Moonshot Partner

Infleqtion says it was the only foreign quantum computing partner chosen by JST for the Quantum Moonshot program. That status is the diplomatic fact hiding under the hardware photo. When the company joined, Rahm Emanuel, then the US ambassador to Japan, called a US quantum firm inside the Moonshot a step in the US-Japan alliance on a contested technology.

Gokhale’s launch line treats the Japanese machine as proof of Infleqtion’s own platform, which is the vendor reading of a lab the Japanese institute says it leads.

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. 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.

Pranav Gokhale, Chief Technology Officer, Infleqtion

The sharper industrial question is whether Infleqtion wants to keep selling processors into other people’s stacks. IMS integrates. Hitachi writes software. Infleqtion delivers the QPU. That is a merchant-silicon pattern, and it is also how a US company gets inside a Japanese national program without owning the computer that program will put on the network.

Infleqtion is running the same pattern in more than one allied lab. On July 22, 2026, the company said it would put a fault-tolerant neutral-atom machine at the Illinois Quantum and Microelectronics Park in 2027, and that the Illinois plan builds on deployments in the United Kingdom and Japan. Shunkai is one node in that map, not Infleqtion’s only shipped processor.

https://x.com/infleqtion/status/2091918810668310583

Ohmori Wants Shunkai Tied to Supercomputers

IMS says Shunkai will be partly opened to outside users so theory and software groups can work on error correction and so company labs can try applications. The 2028 JST milestone keeps those first outside users inside the Ohmori project. The 2030 milestone is when people outside the project are supposed to run logical circuits. Until those doors open on a published schedule, “external use” is a plan IMS has stated, not a queue anyone can join from a webpage.

Ohmori’s other target sits in the same building as the atoms. He wants Shunkai wired to IMS’s shared supercomputer so the site becomes a quantum-GPU hybrid center, with quantum jobs and classical GPU jobs on the same fabric.

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. We expect that the external use of our full-stack machine Shunkai, for example, by the theory and software researchers for the development of error-correction technologies, and by the corporate researchers toward practical applications would lead to ripple effects on various fields in industry, academia, and government around the world. It is also expected that Shunkai will be integrated with the existing shared supercomputer facility at the IMS to develop into a quantum-GPU hybrid computing center.

Kenji Ohmori, Professor and Chairman, Institute for Molecular Science

The machine that went live on August 24, 2026 is a 50-qubit IMS-Hitachi stack with an Infleqtion processor, named for an Edo astronomer, and parked under a Moonshot clock that runs to March 2031. The QPU vendor is the only foreign company JST let into that program. The lab that switched it on still owns the computer.