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 R&D Centre, together with the planned deployment of a Quantinuum Helios system in Singapore, aims to accelerate industrial collaboration across pharma, materials and finance, while bolstering the local quantum ecosystem and workforce
March 11, 2026 – Singapore – Quantinuum, a leading quantum computing company, today announced the establishment of a new R&D and Operations Centre (the “Centre”) in Singapore, marking its formal expansion into Singapore. This important development will enable Quantinuum to deepen collaboration with the nation’s research and industrial ecosystem, together with the company’s plan to deploy its Helios quantum computer in Singapore later this year.
Singapore’s early investment in quantum has positioned the nation to capture value as quantum systems move toward real-world use. In his national budget speech last month, Prime Minister Mr. Lawrence Wong highlighted Quantinuum as an industry leader, emphasizing that Helios will enable Singaporean researchers and companies to work on meaningful projects.
The new Centre will bring together Quantinuum staff with local researchers and industry partners to co-develop commercially relevant solutions across pharma, materials science, finance, and other sectors. It will also serve to help advance Singapore’s national priorities under its National Quantum Strategy by strengthening long-term R&D capabilities and workforce development, helping position Singapore as a global hub for quantum technology.
The Centre’s establishment is supported by the Singapore Economic Development Board (EDB) and builds on Quantinuum’s close partnership with Singapore’s National Quantum Office (NQO) through the National Quantum Computing Hub. The National Quantum Strategy is developed and implemented by NQO, which is hosted in the Agency for Science, Technology and Research (A*STAR), and funded by the National Research Foundation (NRF).
As part of its commitment to developing a robust local ecosystem and support for innovation across the full quantum value chain, Quantinuum is collaborating with pioneering startups in Singapore, including Entropica, which accesses Quantinuum systems through its Startup Partner Program, and Squareroot8, with whom Quantinuum signed a Memorandum of Understanding today to co-develop quantum communications applications.
Official Statements
- Dr. Rajeeb Hazra, President and CEO of Quantinuum, said: “We believe there are three pillars to a holistic strategy for building a sustainable quantum frontier: use cases, infrastructure, and workforce. Singapore provides an exceptional foundation for this approach, and we are proud to contribute our experience in ecosystem development as we build a leading quantum ecosystem together."
- Dr. Marvin Lee, Country Leader for Quantinuum Singapore, who recently joined the company following senior appointments at A*STAR, EDB, and NRF, where he played a key role in shaping the National Quantum Strategy, said: “The new Centre will enable local talent and industry to work hands-on with quantum technologies, co-develop solutions aligned with national priorities, and support high-value jobs. We are committed to building long-term capability and resilience in Singapore’s digital economy."
- Mrs. Josephine Teo, Minister for Digital Development and Information, a key advocate of the National Quantum Strategy, joined Quantinuum today as the Guest of Honour at the official opening of its new Centre, commemorated by a formal ribbon-cutting ceremony. She said: “Singapore aims to be a global hub for the development of algorithms and applications for quantum computers. We will tap on our strengths in sectors of potential application, such as finance, logistics, and pharmaceuticals. Doing so will not only benefit these industries in Singapore, but elsewhere in the world.”
- Mr. Pee Beng Kong, Executive Vice President, Singapore Economic Development Board, said: “Quantinuum’s expansion into Singapore marks an important step in translating quantum research into real-world industry applications. The Helios system and new R&D Centre will enable local companies and researchers to collaborate on next-generation solutions in areas such as drug discovery, materials innovation, and financial optimisation. This investment will deepen partnerships across our industry and research ecosystem and build high-value quantum capabilities from Singapore.”
- Mr. Ling Keok Tong, Executive Director of the National Quantum Office, said: “Quantinuum's R&D Centre and the Helios deployment create opportunities for Singapore, giving our researchers hands-on access to advanced quantum hardware, and moves us closer to demonstrating real quantum advantage in drug discovery, portfolio optimisation, amongst others. This is a boost to our quantum research and talent development, as well as our efforts in building a robust quantum ecosystem.”
The new Centre represents an important step in Quantinuum’s international expansion and its commitment to collaborating with partners in key innovation hubs. Quantinuum looks forward to continued collaboration with Singapore’s research and industry ecosystem to advance the development and application of quantum technologies.
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 fidelity1. 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.
1. As of December 31, 2025.
Source: PRNewswire - Honeywell
Charlotte, N.C., Jan. 14th 2026 — Honeywell (NASDAQ: HON) today announced that Quantinuum LLC ("Quantinuum" or the "Company"), which is majority owned by Honeywell, plans to make a confidential submission of a draft registration statement on Form S-1 to the U.S. Securities and Exchange Commission (the "SEC") 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.
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With the industry's most advanced quantum systems and proven ability to scale, Quantinuum is on track to deliver utility-scale quantum computing by early 2030s
November 6, 2025 – Broomfield, CO – Quantinuum, the world leader in quantum computing, has been selected by the Defense Advanced Research Projects Agency (DARPA) as a contractor to advance to Stage B of DARPA’s Quantum Benchmarking Initiative (QBI).
DARPA is using QBI to evaluate the technical likelihood that a utility scale quantum computer will be available no later than 2033. A multi-stage program, Stage B follows a six-month Stage A effort in which Quantinuum developed and delivered a detailed concept design for a utility scale system called “Lumos.”
Last year, Quantinuum released its public roadmap through the end of the decade with Apollo—a universal, fully fault-tolerant quantum computer—scheduled for launch in 2029. Lumos is a new addition to the roadmap as Quantinuum outlines plans to develop increasingly larger systems into the 2030s.
“This selection recognizes the strength and maturity of our roadmap and the work our teams have already delivered,” said Dr. Rajeeb Hazra, President and CEO of Quantinuum. “Lumos extends our roadmap into the next decade and gives DARPA a concrete, de-risked path for achieving utility-scale quantum computing by 2033. We look forward to partnering with DARPA and our ecosystem partners to advance this important national objective.”
Stage B will be a year-long, performance-based evaluation by DARPA’s Test and Evaluation team in which Quantinuum will develop a detailed R&D roadmap for Lumos to validate technical assumptions, verification methods, and scaling plans to meet the 2033 objective.
Yesterday, Quantinuum deployed its latest generation system, “Helios,” on schedule with its roadmap. With the highest fidelity physical qubits and logical qubits of any commercial system, and a next-generation software stack featuring a modern, high-level programming language, Helios is designed to accelerate quantum computing adoption. The system has already been used to simulate high-temperature superconductivity and magnetism at unprecedented scales—two applications with relevance to critical, industrial utility.
About Quantinuum
Quantinuum is the world leader in quantum computing. The company’s quantum systems deliver the highest performance across all industry benchmarks. Quantinuum’s over 630 employees, including 370+ scientists and engineers, across the US, UK, Germany, and Japan, are driving the quantum computing revolution.
For more information, please visit www.quantinuum.com