Quantum Chemistry Progresses Meaningfully Towards a Fault Tolerant Regime Using Logical Qubits

In a major scientific first, quantum chemistry experts at Quantinuum have used a partially fault tolerant algorithm run on logical qubits to simulate the hydrogen molecule (H2)

July 12, 2023

Tokyo, Japan, Cambridge, UK, and Broomfield, Colorado, July 12th, 2023 — Quantinuum, the world’s largest quantum computing company, has become the first to simulate a chemical molecule by implementing a partially fault tolerant algorithm on a quantum processor using logical qubits. 

This essential step towards using quantum computers to speed up molecular discovery, with better modeling of chemical systems, reduces the time to generate commercial and economic value.

Quantinuum scientists, led from Japan, used three logical qubits on Quantinuum’s H1 quantum computer to calculate the ground state energy of the hydrogen molecule (H2) using an algorithm for early fault tolerant devices called stochastic quantum phase estimation.

It is already known that many algorithms that can be used on today’s “NISQ” era quantum computers will not scale to larger problems. The phase estimation technique used in this experiment with logical qubits has better potential to scale but is challenging to implement on today’s quantum computers because it requires very complex circuits, which are prone to failing due to noise. 

Dr. Raj Hazra, CEO of Quantinuum, said: “Today’s announcement turns a page for quantum chemistry on quantum computers, moving us towards the era of early fault tolerance. This achievement is testament to the dedication of the hardware and software teams at Quantinuum, who consistently demonstrate their ability to achieve world-class results. It was made possible thanks to the H1 quantum computer which brings together high-fidelity gate operations, all-to-all connectivity and conditional logic, with the truly world-leading algorithms, methods and error handling techniques offered by our InQuanto chemistry platform.”

In a scientific preprint paper, “Demonstrating Bayesian Quantum Phase Estimation with Quantum Error Detection”, the team of scientists led by Dr. Kentaro Yamamoto report they have overcome this challenge by creating and using logical qubits achieved with a newly developed error detection code designed for the H-series quantum hardware*. The code saved quantum resources by immediately discarding a calculation if it detected qubits that had produced errors during the computation process.

When combined with the low noise of the H-Series hardware and the capabilities of the Quantinuum Software InQuanto™, researchers were able to run these complex circuits for the first time, producing more accurate simulation results than those achieved without the error detection code. Creating and using logical qubits with error detection is a prerequisite for the more advanced error correction, which provides real-time protection for a quantum computer against various forms of “noise”.

Dr. Kentaro Yamamoto, Senior Researcher at Quantinuum, said: “Simulating the hydrogen molecule and getting such good results with logical qubits is an excellent experimental result and reminds us how fast we continue to progress. This result may reflect the start of a new chapter for quantum computing professionals, where we can begin to adopt partially fault tolerant algorithms on near-term devices, using all the techniques that will ultimately be required for future large-scale quantum computing.”

For scientific researchers and industrial enterprises in sectors such as healthcare, energy, automotive and manufacturing, who invest heavily in researching future molecules and materials, this demonstration implies that the time to useful quantum computing continues to get nearer.

This demonstration, which was run on Quantinuum’s System Model H1 quantum computer, Powered by Honeywell, will be integrated into future versions of its industry-leading quantum computational chemistry platform, InQuanto, allowing industrial companies and academic researchers to explore the use of partially fault-tolerant algorithms run on quantum computers for material and molecular modeling.

* For more information about the error detection code, see “Protecting Expressive Circuits with a Quantum Error Detection Code”

About Quantinuum

Quantinuum is the world’s largest standalone quantum computing company, formed by the combination of Honeywell Quantum Solutions’ world-leading hardware and Cambridge Quantum’s class-leading middleware and applications. Science-led and enterprise-driven, Quantinuum accelerates quantum computing and the development of applications across chemistry, cybersecurity, finance and optimization. Its focus is to create scalable and commercial quantum solutions to solve the world’s most pressing problems in fields such as energy, logistics, climate change, and health. The company employs over 480 individuals, including 350+ scientists and engineers, at eight sites across the United States, Europe, and Japan. For more information, please visit https://www.quantinuum.com. The Honeywell trademark is used under license from Honeywell International Inc. Honeywell makes no representations or warranties with respect to this service.

About Quantinuum

Quantinuum, the world’s largest integrated quantum company, pioneers powerful quantum computers and advanced software solutions. Quantinuum’s technology drives breakthroughs in materials discovery, cybersecurity, and next-gen quantum AI. With over 500 employees, including 370+ scientists and engineers, Quantinuum leads the quantum computing revolution across continents. 

May 5, 2026
Quantinuum and BMW Group Expand Landmark Quantum Computing Collaboration with New Multi-Year Partnership
  • The companies plan to continue their co-creation partnership to advance future mobility
  • BMW to access the latest generations of Quantinuum systems throughout the partnership
  • Advanced materials science research supports a range of next-generation technologies

Broomfield, Colorado, May 5th, 2026 — Quantinuum and BMW Group have formally expanded their ongoing collaboration into a multi-year partnership with a mission to unlock future mobility by applying quantum computing toward advanced materials science.

Since 2021, Quantinuum and BMW Group have been collaborating on joint research focused on tackling complex challenges in industrial chemistry to support the advancement of next-generation mobility. The collaboration has progressed from foundational algorithm development to advanced simulations of molecular systems, allowing the researchers to unlock insights into catalytic activity, reaction pathways, and material performance in energy-relevant environments.

The companies have now agreed to extend the work, positioning the alliance to become one of the longest-sustained commitments between a commercial enterprise and a quantum computing provider to date.

“Quantinuum is focused on driving commercial adoption of quantum computing through close collaboration with industry leaders on high-impact applications," said Dr. Rajeeb Hazra, President and CEO of Quantinuum. “Our expanded partnership with the BMW Group underscores this focus, and we’re excited to scale the meaningful work we’ve been advancing together.”

Researchers at BMW Group are utilizing Quantinuum's trapped-ion architecture, which provides the high-fidelity operations necessary to accurately simulate molecular systems, particularly electrochemical processes that play a critical role across a range of technologies relevant to sustainable mobility and the design and optimization of fuel cells.

Under the terms of the agreement, BMW Group will leverage successive generations of Quantinuum’s quantum computers. This includes the current Helios system and upcoming generations, Sol (planned for 2027) and Apollo (planned for 2029). This will enable the teams to validate progress at each stage while scaling toward industrially meaningful solutions.

“We have been exploring quantum computing for many years,” said Dr. Martin Tietze, Vice President of New Technologies at BMW Group. “Together with partners such as Quantinuum, we translate advances in quantum hardware into real‑world applications, including materials optimization, supporting the development of future vehicle generations.”

Quantinuum’s progress toward large-scale, fault-tolerant systems helps to ensure that as the hardware reaches milestones in performance, BMW can apply that computational power to catalyst chemistry research, targeting critical oxygen reduction reaction processes at platinum catalysts to potentially lower costs and improve energy efficiency.

The companies broke new ground in 2024, alongside another commercial partner, as the first to simulate catalytic performance using a quantum computer with results published in Nature Partner Journal.

Beyond its technical achievements, the collaboration has evolved into a deeply connected, cross-disciplinary effort, bringing together quantum scientists, chemists, and engineers in a sustained partnership that reflects both the complexity of the challenge and the scale of the ambition.

About Quantinuum

Quantinuum is a leading quantum computing company offering a full-stack platform designed to make quantum computing deployable in real-world environments. The company has commercially deployed multiple generations of quantum systems built on the well-established QCCD architecture, which it has implemented with novel designs and capabilities to achieve the industry’s highest accuracy levels based on average two-qubit gate fidelity.[i] Quantinuum has active engagements with market leaders across pharmaceuticals, material science, financial services, and government and industrial markets.

The company has a global workforce of approximately 700 employees, including top scientists and researchers. Over 70% of its technology team hold PhDs or Master's degrees. Quantinuum’s headquarters is in Broomfield, Colorado, with additional facilities across the United States, United Kingdom, Germany, Japan, and Singapore.  

For more information, please visit www.quantinuum.com.

[i] As of December 31, 2025.

This is some text inside of a div block.
All
This is some text inside of a div block.
All
This is some text inside of a div block.
All
April 22, 2026
Honeywell Announces Quantinuum’s Confidential Submission of Draft Registration Statement for Proposed Initial Public Offering

Source: PRNewswire - Honeywell

Charlotte, N.C., April 22nd, 2026 — Honeywell (NASDAQ: HON) today announced that Quantinuum LLC (“Quantinuum” or the “Company”), which is majority owned by Honeywell, confidentially submitted a draft registration statement on Form S-1 to the U.S. Securities and Exchange Commission (the “SEC”) on February 17, 2026, relating to the proposed initial public offering of Quantinuum’s common stock. The number of shares to be offered and the price range for the proposed offering have not yet been determined. The offering is subject to market and other conditions and the completion of the SEC’s review process.

This press release is being made pursuant to, and in accordance with, Rule 135 under the Securities Act of 1933, as amended (the “Securities Act”), and shall not constitute an offer to sell, or the solicitation of an offer to buy, any securities. Any offers, solicitations or offers to buy, or any sales of securities, will be made in accordance with the registration requirements of the Securities Act.

Contacts:

Media
Stacey Jones
(980) 378-6258
Stacey.Jones@honeywell.com

Investor Relations
Mark Macaluso
(704) 627-6118
Mark.macaluso@honeywell.com

This is some text inside of a div block.
All
This is some text inside of a div block.
All
This is some text inside of a div block.
All
April 16, 2026
RIKEN Scales Quantum-Supercomputing in Japan with Quantinuum System Upgrade

Tokyo, Japan, April 14th, 2026 — Quantinuum, a leading quantum computing company, today announced that RIKEN, Japan’s premier national research institute, has procured its System Model H2 quantum computer to scale the capability of “Reimei-Fugaku,” a hybrid quantum-supercomputer platform in Japan.

The Reimei-Fugaku platform represents the frontier of computing technology. Launched in the spring of 2025, it combines Quantinuum’s "Reimei" quantum system with RIKEN’s "Fugaku," one of the world’s fastest supercomputers—more formally known as a high-performance computing (HPC) system.

Now, the hybrid compute platform is getting a substantial upgrade. Earlier this month, Quantinuum delivered its H2 system to RIKEN’s research facility near Tokyo, where assembly is already underway to replace its predecessor, System Model H1, which Reimei has been based on to date. The newer-generation, 56-qubit system is engineered for high-fidelity operations that can reduce time-to-solution, enable larger workloads, and support higher-value applications.

Technology leaders see hybrid compute systems as a practical way to overcome the limits of classical HPC. By combining the significant data-processing power of HPC with a quantum computer’s ability to model complex molecules and materials, researchers could be enabled to solve specialized mathematical problems that are impractical for classical systems to handle alone.  

Researchers have already demonstrated this potential using the current Reimei-Fugaku platform. In a workflow with relevance potentially extending to future pharmaceutical applications, they successfully simulated biomolecular reactions at an accuracy that would be infeasible for HPC to achieve in isolation.

With multiple studies in chemistry and materials science already underway on the platform, this H2 upgrade is expected to accelerate research and unlock even more complex scientific discoveries across disciplines.

Dr. Mitsuhisa Sato, Division Director of the Quantum-HPC Hybrid Platform Division, RIKEN Center for Computational Science, said: “Since its installation in February 2025, Reimei H1 has been widely used by JHPC-quantum users and has delivered significant results, thanks to its high fidelity and flexible qubit connectivity. The upgrade to H2 is exactly what we have been eagerly anticipating, and with its 56 qubits, we expect it to play a key role in demonstrating quantum advantage through quantum–HPC hybrid computing.”

Dr. Rajeeb Hazra, President and CEO of Quantinuum, said: “We believe RIKEN’s decision to continue adopting Quantinuum systems to meet its ambitious objectives is a validation of our technology roadmap and a reflection of the success of our valued partnership. With Quantinuum and RIKEN’s combined leadership in quantum and HPC, respectively, we expect to continue pushing the boundaries of computing to address some of the most critical and complex challenges facing science and industry today.”

This development reflects the continued progress of Quantinuum and RIKEN’s collaboration to advance quantum-HPC hybrid infrastructure in Japan. Quantinuum intends to continue working with the country’s research community to accelerate real-world use cases and contribute to the growth of its quantum ecosystem.

About RIKEN

RIKEN, a National Research and Development Agency, is Japan’s leading national comprehensive research institution renowned for high-quality research in a diverse range of scientific disciplines. Founded in 1917, initially as a private research foundation, RIKEN has grown rapidly in size and scope, today encompassing a network of world-class research centers and institutes across Japan.

About Quantinuum

Quantinuum is a leading quantum computing company offering a full-stack platform designed to make quantum computing deployable in real-world environments. The company has commercially deployed multiple generations of quantum systems built on the well-established QCCD architecture, which it has implemented with novel designs and capabilities to achieve the industry’s highest accuracy levels based on average two-qubit gate fidelity.[i] Quantinuum has active engagements with market leaders across pharmaceuticals, material science, financial services, and government and industrial markets.

The company has a global workforce of approximately 700 employees, including top scientists and researchers. Over 70% of its technology team hold PhDs. Quantinuum’s headquarters is in Broomfield, Colorado, with additional facilities across the United States, United Kingdom, Germany, Japan, and Singapore.  

For more information, please visit www.quantinuum.com.  

[i] As of December 31, 2025.

This is some text inside of a div block.
All
This is some text inside of a div block.
All
This is some text inside of a div block.
All