Logical qubits start outperforming physical qubits
Quantinuum closes in on breakeven point in quantum error correction
Broomfield, Colorado, August 4th, 2022 — Quantinuum researchers have hit a significant milestone by entangling logical qubits in a fault-tolerant circuit using real-time quantum error correction. The research, published in a new scientific paper that was released on August 3rd, is the first experimental comparison study of different quantum error correction codes in similar environments and presents a collection of several different experiments. These experiments include:
- The first demonstration of entangling gates between two logical qubits done in a fully fault-tolerant manner using real-time error correction
- The first demonstration of a logical entangling circuit that has higher fidelity than the corresponding physical circuit.
This milestone achievement is important because it marks the first time that logical qubits have been shown to outperform physical qubits — a critical step towards fault-tolerant quantum computers.
“Quantinuum’s trapped-ion quantum computing roadmap is designed around continuous upgrades, enabled our flexible architecture and our precision control capabilities. This combination provides for outstanding, first-of-its-kind achievements that help accelerate the entire industry,” said Tony Uttley, President and COO of Quantinuum.
David Hayes, a Theory and Architecture Technical Manager at Quantinuum and co-author of the new research paper, said the research moves quantum computing closer to the point where encoded circuits outperform more primitive operations.
“People have worked with error corrected qubits before, but they haven't reached this sort of special point where the encoded operation is working better than the primitive operation,” Hayes said. “The other thing that's new here is that in other experiments we're doing the error correction while we're doing the operations. An important next step for us is to get the error rate induced by the error correction itself down further."
The findings are described in the new research paper, “Implementing Fault-tolerant Entangling Gates on the Five-Qubit code and the Color Code”. The paper was recently published on the arXiv. Scientists used both the H1-1 and the H1-2 quantum computers, Powered by Honeywell, to compare the Five-Qubit error code and the Distance Three Color Code in these tests.
Quantum researchers are in the early days of experimental quantum error correction with a multitude of codes to test. Quantinuum researchers can explore a wider range of quantum error codes, compared to other quantum hardware designs, due to the architecture of the machine.
The System Model H1 uses a trapped-ion design and a quantum charged coupled device architecture (QCCD). Along with the inherent flexibility of this design, another strength is all-to-all connectivity. All the qubits are connected to each other which makes it easy to move information through chains of ions without creating multiple errors along the way.
“Instead of having to build a new machine every time we want to try a new code, we can just program the machine to run a different code, make the measurements and weigh the different pros and cons,” Hayes said.
Advancing quantum error correction
All forms of technology need error correction including servers in data centers and space probes sending transmissions back to Earth. For Quantinuum and other companies in the quantum computing sector, quantum error correction is one of the most important pillars of progress. Errors prevent quantum computers from producing reliable results before they are overwhelmed. Quantinuum’s researchers are working toward the milestone of fault tolerance, meaning the errors can be suppressed to arbitrarily low levels.
Natalie Brown, another co-author of the paper and an Advanced Physicist at Quantinuum, said that most classical error correction principles fail with quantum computers because of the basic nature of quantum mechanics.
“It becomes very difficult to suppress noise to very small levels, and that becomes a problem in quantum computing,” she said. “The most promising candidate was this quantum error correction, where we take the physical qubits, make a logical qubit.”
Logical qubits are groups of physical qubits working together to perform a computation. For each physical qubit used in a computation, other ancillary qubits perform a range of tasks such as spotting and correcting errors as they occur.
Ciaran Ryan-Anderson, a Senior Advanced Physicist at Quantinuum and also a co-author of the new paper, said the newest research paper builds on research performed in 2021 and published in Physical Review X. That work explained how researchers at Honeywell Quantum Solutions applied multiple rounds of quantum error correction to a single logical qubit.
“One of the first really important things to demonstrate was these repeated rounds of quantum error correction cycles,” he said.
That is one of several milestones on Ryan-Anderson’s quantum error correction checklist:
- Conduct repeated rounds of fault tolerant quantum error correction
- Feed forward and conditionally apply syndrome extraction
- Enable real-time determination of correction for a quantum error correction code
- Demonstrate general algorithmic real-time decoding
- Scale up quantum error correction with two logical qubits
- Hit the breakeven point when logical quantum computing starts to outperform physical quantum computing
“Quantinuum has achieved some of the milestones required to accomplish this now,” Ryan-Anderson said.
Five-Qubit Code vs. Color Code
Building upon the 2021 research involving one logical qubit, the newest research illustrates the Quantinuum team’s progress with quantum error correction and two logical qubits. The team tested two error codes familiar to quantum experts: the Five-Qubit Code and the Color Code. The Five-Qubit Code does not allow for a fault tolerant transversal gate using only two logical qubits. Researchers used “pieceable” fault tolerance to decompose an initially non-fault tolerant logical gate operation into pieces that are individually fault-tolerant. The Color Code, however, does allow the use of a transversal CNOT gate which is naturally fault-tolerant.
How the experiment worked
H1-2 can use up to 12 qubits and H1-1 can use up to 20. The Five-Qubit Code tested on H1-2 while the Color Code tested on H1-1. Both computers use the same surface electrode ion trap to control ytterbium ions as qubits. Ion transport to isolated gate zones with focused laser beams provides low crosstalk gate and mid-circuit measurement operations.
The researchers ran five experiments with different combinations of circuit elements to test the Five-Qubit Code and to understand the impact of fault tolerant design and circuit depth. The team found that the extra circuitry designed to increase fault tolerance had a negative impact on the overall fidelity of the logical operation, due to the large number of CNOT operations required.
The Color Code showed much better results due in part to the ability to use a transversal CNOT gate. The team ran seven experiments to investigate the fault tolerant potential of these codes. With the Color Code, the researchers found that the State Preparation and Measurement circuits benefitted from the addition of fault tolerant circuitry with a significant reduction of error rates: 99.94% for the logical qubits compared to 99.68% for the physical qubits. This was the only additional circuitry required to make the circuit fault tolerant from end-to-end, since the logical CNOT is transversal and naturally fault tolerant.
The researchers concluded that the “relatively economical fault tolerant circuitry of the Color Code will provide a better platform for computation than the qubit efficient five-qubit code.” Also, the researchers found that the Five-Qubit Code would be useful only in systems with far lower physical error rates than quantum computers have at this point in time.
Hayes said the team’s next step will be to surpass the breakeven point and provide proof of the work. “We are getting evidence that we're really darn close to that point, but there's a lot of work that needs to be done to actually prove it,” he said. “Just getting right there is not good enough, you have to actually get past it.”
A new classical+quantum connection
Another advance from this experiment is a new classical processor with enhanced capabilities which will be essential to scalable algorithmic decoders. The data from the classical functions were used to dictate the control flow and operations executed in the quantum program.
The decoders used in these experiments were partially written in Rust and compiled to WebAssembly (Wasm). The choice of Wasm provides an efficient, safe, and portable classical language to have functions that are callable from quantum programs.
The decoder implemented in Rust uses many high-level program constructs. The support for these features means that various scalable algorithmic decoders can be ergonomically implemented in various high-level languages that compile to Wasm (such as Rust, C, and C++) and called from quantum programs.
“It was pretty enabling for this particular experiment, and it'll be even more important for future experiments as these things get more and more complicated,” Hayes said.
Another advantage of the trapped ion architecture is the ability to do real-time decision making during the execution of the quantum circuit thanks to long coherence times and the ability to do mid-circuit measurement and reset qubits as needed.
“Our systems have very long coherence times which is super advantageous when integrating in the classical compute real-time decision making,” Hayes said.
The Honeywell Trademark is used under license from Honeywell International Inc. Honeywell International Inc. makes no representations or warranties with respect to this product. This product is produced by Quantinuum.
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.
- The federal funding supports critical R&D and U.S. quantum semiconductor manufacturing capabilities needed to scale fault-tolerant trapped-ion quantum computing.
- Company partnering with GlobalFoundries to fabricate next-gen ion traps and control electronics, and Monarch Quantum to develop and manufacture reliable lasers and optical components.
Washington, D.C. – September 8, 2026 – Quantinuum (Nasdaq: QNT), a leading quantum computing company, today announced it has finalized an agreement with the U.S. Department of Commerce’s CHIPS Research and Development Office for $100 million in federal funding deployed through the CHIPS and Science Act. The award, which follows a letter of intent announce in May, supports R&D and U.S. quantum semiconductor manufacturing capabilities needed to deploy large-scale, fault-tolerant trapped-ion quantum computers.
Quantinuum, which was the only company with a trapped-ion based architecture to be awarded CHIPS R&D funding, develops the world’s most accurate commercial1 computers with industry-leading error correction fidelity.2 The company leverages established semiconductor manufacturing processes to help ensure reliability, repeatability, and scalability of the company’s current and future quantum computers.
“This award is a validation of Quantinuum’s leadership in trapped-ion quantum computing," said Dr. Rajeeb Hazra, President and CEO of Quantinuum. “Together with our domestic partners, we are building the technology and supply-chain foundation needed to scale fault-tolerant systems and strengthen America's leadership in this strategically important field.”
The award will support R&D that the company expects to help strengthen and diversify its supply chain, adding onshore partners GlobalFoundries and Monarch Quantum. GlobalFoundries will be one of several of Quantinuum’s foundries enlisted to fabricate its next-generation ion traps and other electronics, specifically focused on using 300mm wafer technology; Monarch Quantum plans to develop and manufacture scalable, reliable lasers and optical components required for Quantinuum’s trapped-ion systems.
“As quantum computing moves closer to commercial scale, manufacturing will be critical to unlocking its full potential,” said Tim Breen, CEO of GlobalFoundries. “GlobalFoundries is proud to partner with Quantinuum to help scale their trapped-ion technology. By bringing our expertise in high-volume, differentiated semiconductor manufacturing, we're helping create a path to more scalable, reliable quantum hardware and advancing the next generation of American innovation.”
“The road to large-scale, trapped-ion quantum computers relies on moving away from complex, sprawling optical setups to scalable, reliable integrated photonics engines," said Dr. Timothy Day, CEO of Monarch Quantum. "We are honored to expand our partnership with Quantinuum to advance their hardware roadmap and to help strengthen U.S. leadership in quantum computing manufacturing and supply chain resilience.”
Together, these efforts are intended to reduce system complexity and improve component robustness, reliability, and reproducibility, ultimately supporting the continued scaling of trapped-ion quantum computers, while strengthening domestic capability across critical photonics and semiconductor manufacturing.
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 trapped-ion based 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.3 Quantinuum has active engagements with market leaders across pharmaceuticals, material science, financial services, and government and industrial markets, as well as academic and research institutions globally. The company has a global workforce of over 800 employees, including top scientists and researchers. Quantinuum’s headquarters is in Broomfield, Colorado, with additional facilities across the United States, United Kingdom, Germany, Japan, Qatar, and Singapore. For more information, please visit www.quantinuum.com.
Cautionary Statement Concerning Forward-Looking Statements
This press release contains certain statements that may be deemed “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements that are not historical facts. The words “anticipate,” “assume,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “future,” “will,” “seek,” “foreseeable,” the negative version of these words, or similar terms and phrases are intended to identify forward-looking statements. Such statements are based on certain assumptions and assessments made by our management in light of their experience and their perception of historical trends, current economic and industry conditions, expected future developments and other factors they believe to be appropriate. The forward-looking statements included in this release are also subject to a number of material risks and uncertainties, including but not limited to economic, competitive, governmental, and technological factors affecting our operations, markets, products, services and prices. New factors emerge from time to time, and it is not possible for Quantinuum to predict all such factors. For additional information on these and other risks that could affect Quantinuum’s forward-looking statements, see Quantinuum’s risk factors discussed in its filings with the U.S. Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the period ended June 30, 2026, as such risk factors may be updated from time to time. Any forward-looking statement speaks only as of the date on which it is made, and, except as required by law, Quantinuum does not undertake any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.
1 Based on physical two-qubit gate fidelity as of December 31, 2025, according to the 2025 Ransford et al. study.
2 As of February 25, 2026, according to the 2026 Dasu et al. study.
3 As of December 31, 2025.
BROOMFIELD, Colo., September 4, 2026 - Quantinuum Inc. (Nasdaq: QNT) (the “Company”), a leading quantum computing company, today announced that members of its management team will participate in the Bernstein 23rd Annual Pan-European Strategic Decisions Conference, taking place September 9–10, 2026, in London, United Kingdom.
Quantinuum will participate in a fireside chat and host one-on-one meetings with investors during the conference.
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 trapped-ion based 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. Quantinuum has active engagements with market leaders across pharmaceuticals, material science, financial services, and government and industrial markets, as well as academic and research institutions globally.
The company has a global workforce of approximately 800 employees, including top scientists and researchers. Over 70% of its technology team holds PhDs or Master’s degrees. Quantinuum’s headquarters is in Broomfield, Colorado, with additional facilities across the United States, United Kingdom, Germany, Japan, Qatar, and Singapore.
Contacts
Investor & Media Contact
Shub Mukherjee - Investor Contact - investors@quantinuum.com
Aaron Sorenson - Media Contact - press@quantinuum.com
Non-binding Memorandum of Understanding (MOU) aims to support innovation and operational excellence within the energy sector.
Riyadh, August 31, 2026: Quantinuum, a leading quantum computing company, today announced the signing of a non-binding MOU with Aramco, one of the world’s leading integrated energy and chemicals companies, to explore a series of industrial use cases, enhance quantum computing capabilities, and prepare for a potential research collaboration focused on fault-tolerant quantum computing.
Under the MOU, the companies intend to undertake preliminary technical onboarding and engage in knowledge exchange activities. They will also identify Aramco’s challenges that may be suitable for quantum computing research with an emphasis on solving complex problems in energy and digital transformation. The collaboration aims to assess how future generations of quantum systems may address relevant scientific and industrial challenges, and to benchmark different quantum computing modalities.
The collaboration complements Aramco’s existing initiatives to position itself as a leader in the application of advanced quantum technologies within the energy industry, reinforcing its efforts towards supporting the digital transformation of the sector and contributing to the evolving quantum computing roadmap for the energy industry.
“Organizations that expect to benefit from quantum computing need to begin developing their expertise, algorithms and workflows today,” said Dr. Rajeeb Hazra, President and CEO of Quantinuum. “This MOU creates a framework for Quantinuum and Aramco to exchange expertise, identify important industrial challenges and prepare for a deeper research collaboration. By combining Aramco’s scientific and engineering knowledge with Quantinuum’s integrated hardware and software capabilities, we aim to build a strong foundation for research across future generations of quantum computing.”
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 trapped-ion based 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.1 Quantinuum has active engagements with market leaders across pharmaceuticals, material science, financial services, and government and industrial markets, as well as academic and research institutions globally. The company has a global workforce of over 800 employees, including top scientists and researchers. Quantinuum’s headquarters is in Broomfield, Colorado, with additional facilities across the United States, United Kingdom, Germany, Japan, Qatar, and Singapore. For more information, please visit www.quantinuum.com.
Cautionary Statement Concerning Forward-Looking Statements
This press release contains certain statements that may be deemed “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements that are not historical facts. The words “anticipate,” “assume,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “future,” “will,” “seek,” “foreseeable,” the negative version of these words, or similar terms and phrases are intended to identify forward-looking statements. Such statements are based on certain assumptions and assessments made by our management in light of their experience and their perception of historical trends, current economic and industry conditions, expected future developments and other factors they believe to be appropriate. The forward-looking statements included in this release are also subject to a number of material risks and uncertainties, including but not limited to economic, competitive, governmental, and technological factors affecting our operations, markets, products, services and prices. New factors emerge from time to time, and it is not possible for Quantinuum to predict all such factors. For additional information on these and other risks that could affect Quantinuum’s forward-looking statements, see Quantinuum’s risk factors discussed in its filings with the U.S. Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the period ended June 30, 2026, as such risk factors may be updated from time to time. Any forward-looking statement speaks only as of the date on which it is made, and, except as required by law, Quantinuum does not undertake any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.
1 As of December 31, 2025.