Quantinuum’s H1 quantum computer successfully executes a fully fault-tolerant algorithm with three logically-encoded qubits

A multidisciplinary team from Quantinuum, QuTech (Delft University of Technology) and the University of Stuttgart used the H1 quantum computer to demonstrate a noteworthy advance in fault-tolerant operations

September 28, 2023

Cambridge, UK and Broomfield, Colorado, September 28th, 2023 Fault-tolerant quantum computers that offer radical new solutions to some of the world’s most pressing problems in medicine, finance and the environment, as well as facilitating a truly widespread use of AI, are driving global interest in quantum technologies. Yet the various timetables that have been established for achieving this paradigm require major breakthroughs and innovations to remain achievable, and none is more pressing than the move from merely physical qubits to those that are fault-tolerant.

In one of the first meaningful steps along this path, scientists from Quantinuum, the world’s largest integrated quantum computing company, along with collaborators, have demonstrated the first fault-tolerant method using three logically-encoded qubits on the Quantinuum H1 quantum computer, Powered by Honeywell, to perform a mathematical procedure.

Fault-tolerant quantum computing methods are expected to open the way for practical solutions to real-world problems across domains such as molecular simulation, artificial intelligence, optimization, and cybersecurity. Following a succession of important breakthroughs in recent years in hardware, software and error correction, today's results announced by Quantinuum in a new paper on the arXiv, "Fault-Tolerant One-Bit Addition with the Smallest Interesting Colour Code" are a natural step forward, and reflect the growing pace of progress.

Many companies and research groups are focused on achieving fault-tolerance by handling the noise that naturally arises when a quantum computer performs its operations. Quantinuum is a proven pioneer, achieving previous firsts such as demonstrating entangling gates between two logical qubits in a fully fault-tolerant manner using real-time error correction, and simulating the hydrogen molecule with two logically-encoded qubits

By performing one-bit addition using the smallest-known fault-tolerant circuit, the team achieved an error rate almost an order of magnitude lower, at ~1.1x10-3 compared to ~9.5x10-3 for the unencoded circuit. The error suppression observed was made possible by the physical error rates of the quantum charge-coupled device (QCCD) architecture used in Quantinuum’s H-Series quantum computers, which are lower than in any other systems known to date. These error rates fall within the range at which fault-tolerant algorithms become feasible.

Ilyas Khan, Chief Product Officer and Founder at Quantinuum, said: “In addition to continuing to provide the quantum ecosystem with evidence of what is possible in these early days of quantum computing, the current demonstration is noteworthy for its ingenuity. The ion trap architecture of our H-Series offers the lowest physical error rates and the flexibility derived from qubit transport, which allows users of our hardware to implement a much wider choice of error-correcting codes, and that is what made this possible. Watch out for further important computational advances in the coming period as we link up the quality of our hardware with tasks that are meaningful in the real world.”

Low-overhead logical Clifford gates, in combination with the transversal CCZ gate of the three-dimensional color code, enabled the team to reduce the number of two-qubit gates and measurements required for one-bit addition, from over 1000, to 36.

Ben Criger, Senior Research Scientist at Quantinuum, and principal investigator on the paper, said: “The CCZ gate, which we’ve demonstrated here, is a key ingredient in Shor’s algorithm, quantum Monte Carlo, topological data analysis, and a host of other quantum algorithms. This result proves that real hardware is now capable of running all the essentials of fault-tolerant quantum computing – state preparation, Clifford gates, non-Clifford gates and logical measurement – together.”

About Quantinuum 

Quantinuum is the world’s largest integrated 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. 

March 11, 2026
Quantinuum Expands Global Footprint to Singapore with the Establishment of a New R&D Centre

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 fidelity. 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.

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January 14, 2026
Honeywell Announces Quantinuum's Plan to Make Confidential Submission of Draft Registration Statement for Proposed Initial Public Offering

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.

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

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

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November 6, 2025
Quantinuum Selected by DARPA to Advance to Stage B of Quantum Benchmarking Initiative

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

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