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.
- Quantinuum’s Helios computer achieves a world-record 99.9995% logical fidelity—just five errors in a million operations—using the company’s error-correction architecture.
- Error rate is 10x lower than Quantinuum’s own September 2026 record and 100x lower than the best published result across all other hardware modalities, which was reported by Google Quantum AI using a superconducting system.
- Quantinuum’s successive breakthroughs used different codes on the same hardware, demonstrating how its error-correction architecture and trapped-ion technology drive rapid gains in accuracy, with performance now in the target range for Apollo.
BROOMFIELD, Colo.—October 19, 2026—Quantinuum (NASDAQ: QNT), a leading full-stack quantum computing company, today announced a world-record quantum error-correction result, achieving a logical fidelity of 99.9995% on its Helios commercial computer using the company’s error-correction architecture. This marks Quantinuum’s second breakthrough in two months, demonstrating how its highly accurate trapped-ion hardware and flexible architecture work together to deliver rapid improvements in accuracy.
The achievement reinforces Quantinuum’s error-correction leadership and validates that its accuracy performance is now within the target range for Apollo, the company's planned universal fault-tolerant quantum computer expected to be available by 2029.
Quantinuum’s architecture is an end-to-end framework programmable through the company’s developer platform. It integrates tailored AI decoders, all-to-all qubit connectivity, high-fidelity physical operations, and hardware-level error correction. This architecture also allows the company to test, refine, and combine different error-correction codes and optimize between accuracy and efficiency.
In the latest study, Quantinuum used a well-known “color code” within this architecture to achieve the world-record logical fidelity result, which is equivalent to just five errors per million operations. The error rate is 10 times lower than Quantinuum’s own world record achieved last month and 100 times lower than the best published result across all other hardware modalities, which was reported by Google Quantum AI on a superconducting system.
“With this result, we’ve proven that we have the error-correction architecture and trapped-ion technology required to achieve universal fault-tolerance,” said Dr. Rajeeb Hazra, CEO of Quantinuum. “We have reduced error rates tenfold in rapid succession using a different code on the same commercial hardware, demonstrating the flexibility of our error-correction architecture. We’ve crossed the threshold necessary for exponential improvements in accuracy, reinforcing our path to Apollo and how we can help users unlock commercial value from quantum at scale.”
The study also showed that logical errors fell exponentially as Quantinuum increased the “code distance,” a technique used to understand how many physical qubits are needed to protect quantum information as the error correction scales. Each tested increase reduced the remaining logical errors by a record factor of 12, demonstrating increasingly effective error suppression as the code grows—a critical capability for scaling fault-tolerant quantum computing. Quantinuum believes this result suggests it can deliver fault-tolerance with significantly fewer qubits than are required for other modalities.
“This is a significant milestone that quantum computing researchers have been working toward for many years,” said Robin Blume-Kohout, co-director of Sandia National Laboratories’ Quantum Performance Lab, who was not involved in the study. “The paper demonstrates real, serious performance gains from quantum error correction—a logical qubit nearly 100x better than its component physical qubits. A scaled-up version of this system could reach the reliability required for useful fault-tolerant computation at a feasible size—less than a million physical qubits—which improves the outlook for practical quantum computing. These findings go a long way to retire one of the field’s central technical risks.”
In September 2026, Quantinuum used the same error-correction architecture with its Helix code to demonstrate record-setting logical memory and computation. Both studies ran on the same Helios hardware.
The two demonstrations illustrate how Quantinuum can rapidly prototype different error-correction codes within the same architecture to optimize for relative strengths in accuracy, efficiency, and speed. On Helios, Helix used 10 physical qubits per logical qubit, compared with up to 37 for the color code, while the color code delivered lower logical error rates. This provides insight into which applications pair best with each code as systems advance toward fault-tolerance.
Quantinuum’s error-correction architecture is flexible, allowing for adaptive syndrome extraction, which adjusts error-checking measurements during computation, and chain-mapping, which connects codes suited to different computational tasks. Together with efficient code structures and real-time decoding, these techniques provide multiple ways to reduce errors and resource requirements.
Quantinuum is combining its hardware, error-correction architecture, and full-stack software platform into an integrated system for fault-tolerant quantum computing. As customers prepare for this next era of computing, Quantinuum is providing the tools needed to develop and scale quantum applications capable of addressing challenges across materials science, chemistry, finance, logistics, and other critical sectors.
Read the full research here: quantinuum.com/fault-tolerance-by-2029
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. For more information, please visit www.quantinuum.com.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are intended to be covered by the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact are forward-looking statements, including statements about Quantinuum’s path to and the expected timing of Apollo, its planned universal fault-tolerant quantum computer, by 2029; the expected performance, scalability and resource requirements of Quantinuum’s logical error-correction architecture, error-correction codes and trapped-ion hardware, including the number of physical qubits required to achieve fault tolerance relative to other approaches; the pace of future improvements in logical error rates, Quantinuum’s ability to help customers prepare for and realize commercial value from fault-tolerant quantum computing; and the potential impact of quantum computing on sectors including materials science, chemistry, finance and logistics. Words such as "aim," "anticipate," "believe," "confidence,” "could," "expect," "explore," "intend," "may," “path,” "plan," "potential," "seek," “suggest,” "will," "would" and similar expressions identify forward-looking statements, although not all forward-looking statements contain these words.
Forward-looking statements are based on Quantinuum's current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied. These risks include, among others: the results described in this press release were achieved in experimental settings and may not be able to be replicated at a larger scale, in logical computation, or in commercial use; Quantinuum may be unable to scale its systems, increase qubit counts or integrate its hardware, error-correction framework and software as planned; Quantinuum may not achieve its technology roadmap, including Apollo, on the expected timeline or at all; the pace of technical progress in quantum computing; Quantinuum's ability to maintain the availability and performance of its systems, including Helios; competition, including advances by companies using other quantum computing modalities or architectures; the availability of funding, personnel and government support; and the other risks described under "Risk Factors" in Quantinuum's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026 and its subsequent filings with the Securities and Exchange Commission. Forward-looking statements speak only as of the date of this press release. Quantinuum undertakes no obligation to update any forward-looking statement, except as required by law.
- Quantinuum and The University of Western Australia (UWA) sign MOU to help prepare Australia’s workforce and innovation ecosystem for the hybrid quantum-AI-HPC computing era
- Quantinuum will provide UWA-affiliated researchers, students and entrepreneurs with access to its full-stack quantum computing ecosystem, including Helios, the world's most accurate commercial quantum computer1
- Collaboration will focus on developing quantum applications for sectors critical to Australia's economy, including critical minerals, energy, agriculture, and healthcare
BROOMFIELD, Colo., and PERTH, Australia—October 5, 2026—Quantinuum (NASDAQ: QNT), a leading quantum computing company, today announced the signing of a Memorandum of Understanding (MOU) with The University of Western Australia (UWA) to advance Australia’s quantum capability by expanding access to advanced quantum computing, developing quantum talent, and accelerating the development of practical applications that integrate quantum computing, AI, and high-performance computing (HPC).
Through the collaboration, UWA-affiliated researchers, students, and entrepreneurs will gain cloud-based access to Quantinuum's full-stack quantum computing platform, including Helios, the company's latest-generation quantum computer. The partnership is designed to provide hands-on experience with advanced quantum technologies while creating new opportunities to explore how quantum computing, artificial intelligence, and high-performance computing can work together to address complex real-world challenges.
The organisations will also explore opportunities to expand UWA's Quantum and AI research ecosystem through a university-wide quantum computing applications centre that would bring together academic, industry, and government stakeholders to identify and develop high-value use cases in critical sectors for Australia’s economy, including critical minerals, energy, agriculture, and healthcare.
"Australia has set an ambitious vision for quantum, and it is making meaningful progress toward turning that vision into reality thanks to leadership from institutions like UWA," said Marvin Lee, Quantinuum’s Singapore-based Country Leader. "Together, we're bringing our full suite of capabilities, from world-leading hardware and software to application expertise and ecosystem programs, to develop practical quantum applications and hybrid workflows that will prepare Australia for the quantum era and support the nation's future prosperity."
Beyond providing access to advanced quantum systems, the partnership aims to help build the technical capabilities and innovation networks needed to support Australia's long-term quantum ambitions. Through engagement with Quantinuum programs such as Q-Net and the Startup Partner Program, researchers, developers, and entrepreneurs will have opportunities to access training, collaborate with peers across the global quantum ecosystem, and accelerate the development of quantum-enabled solutions.
Working alongside UWA researchers and industry stakeholders, Quantinuum experts will help evaluate candidate use cases, establish technical benchmarks and assess hybrid workflows that integrate quantum computing, artificial intelligence, and high-performance computing.
Professor Jingbo Wang, founder and Director of UWA’s Research Centre for Quantum Information, Simulation and Algorithm (QUISA), said the partnership built on UWA’s strengths in quantum computing research.
“Through co-design with potential end users and quantum computing hardware providers, this initiative will create new opportunities for UWA researchers, students and industry partners, while strengthening interdisciplinary collaboration across the University. We look forward to exploring all the opportunities this will bring for our researchers as well as student pathways, internships and workforce training initiatives,” Professor Wang said.
“Access to leading quantum technologies helps Australian researchers, students and companies build capability and understand where quantum can deliver real value,” said Petra Andrén, CEO of Quantum Australia. “Collaborations like this create opportunities to develop skills, test applications and connect research with industry challenges. Australia has strengths across the quantum technology stack. Access to the best capabilities, both here and internationally, will help translate those strengths into economic and community benefit.”
The partnership reflects a shared commitment to ensuring Australia remains not only a source of quantum discovery, but a place where quantum technologies are put to work solving real-world challenges and creating economic value.
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. For more information, please visit www.quantinuum.com.
About UWA
For more than 110 years, The University of Western Australia has been a place where ambition meets action. As the state’s first and leading university, we inspire students, researchers and partners to create meaningful change and tackle the world’s most pressing challenges. Located on the banks of the Derbal Yerrigan (Swan River), our main campus stands on land where kaartdjin (knowledge) has been shared for tens of thousands of years. This enduring legacy of learning shapes our diverse global community of more than 28,000 students from 100 countries, connected to a powerful network of over 150,000 graduates making an impact worldwide. Ranked in the global top 100 (QS 2027) and a member of the prestigious Group of Eight, UWA is recognised for excellence in teaching, research and industry collaboration. From sustainability and health to technology and communities, our work drives real-world outcomes.
At UWA, impact starts here. For more information visit: uwa.edu.au
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are intended to be covered by the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact are forward-looking statements, including statements about the expected scope, activities and benefits of the collaboration between Quantinuum and The University of Western Australia; the potential establishment of a university-wide quantum computing applications centre; the development of quantum applications, hybrid quantum-AI-HPC workflows and quantum talent; and the potential impact of quantum computing on sectors including critical minerals, energy, agriculture and healthcare. Words such as "aim," "anticipate," "believe," "could," "expect," "explore," "intend," "may," "plan," "potential," "seek," "will," "would" and similar expressions identify forward-looking statements, although not all forward-looking statements contain these words.
Forward-looking statements are based on Quantinuum's current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied. These risks include, among others: the Memorandum of Understanding is non-binding, and the parties may not enter into definitive agreements or carry out the activities described; the proposed applications centre may not be established; the collaboration may not produce commercially viable applications or the expected benefits; the pace of technical progress in quantum computing; Quantinuum's ability to maintain the availability and performance of its systems, including Helios; competition; the availability of funding, personnel and government support; and the other risks described under "Risk Factors" in Quantinuum's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026 and its subsequent filings with the Securities and Exchange Commission. Forward-looking statements speak only as of the date of this press release. Quantinuum undertakes no obligation to update any forward-looking statement, except as required by law.
1 As of December 31, 2025.
BROOMFIELD, Colo., September 11, 2026 - Quantinuum Inc. (Nasdaq: QNT) (the “Company”), a leading quantum computing company, today announced that members of its management team will participate in the Piper Sandler 5th Annual Growth Frontiers Conference, taking place September 14–16, 2026, in Nashville, Tennessee.
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