Quantinuum and Microsoft achieve breakthrough that unlocks a new era of reliable quantum computing
Quantinuum’s System Model H2 enabled Microsoft’s qubit-virtualization system to generate the most reliable logical qubits ever recorded, a breakthrough with wide ranging implications for everyone in quantum computing, accelerating progress and challenging current assumptions about the timeline toward large scale reliable quantum computing.
By Ilyas Khan, Chief Product Officer and Jenni Strabley, Senior Director Offering Management
Quantinuum and Microsoft have announced a vital breakthrough in quantum computing that Microsoft described as “a major achievement for the entire quantum ecosystem.”
By combining Microsoft’s innovative qubit-virtualization system with the unique architectural features and fidelity of Quantinuum’s System Model H2 quantum computer, our teams have demonstrated the most reliable logical qubits on record with logical circuit error rates 800 times lower than the corresponding physical circuit error rates.
This achievement is not just monumental for Quantinuum and Microsoft, but it is a major advancement for the entire quantum ecosystem. It is a crucial milestone on the path to building a hybrid supercomputing system that can truly transform research and innovation across many industries for decades to come. It also further bolsters H2’s title as the highest performing quantum computer in the world.
Entering a new era of quantum computing
Historically, there have been widely held assumptions about the physical qubits needed for large scale fault-tolerant quantum computing and the timeline to quantum computers delivering real-world value. It was previously thought that an achievement like this one was still years away from realization – but together, Quantinuum and Microsoft proved that fault-tolerant quantum computing is in fact a reality.
In enabling today’s announcement, Quantinuum’s System Model H2 becomes the first quantum computer to advance to Microsoft’s Level 2 – Resilient phase of quantum computing – an incredible milestone. Until now, no other computer had been capable of producing reliable logical qubits.
Using Microsoft’s qubit-virtualization system, our teams used reliable logical qubits to perform 14,000 individual instances of a quantum circuit with no errors, an overall result that is unprecedented. Microsoft also demonstrated multiple rounds of active syndrome extraction – an essential error correction capability for measuring and detecting the occurrence of errors without destroying the quantum information encoded in the logical qubit.
As we prepare to bring today’s logical quantum computing breakthrough to commercial users, there is palpable anticipation about what this new era means for our partners, customers, and the global quantum computing ecosystem that has grown up around our hardware, middleware, and software.
Collaborating to reach a new era
To understand this achievement, it is helpful to shed some light on the joint work that went into it. Our breakthrough would not have been possible without the close collaboration of the two exceptional teams at Quantinuum and Microsoft over many years.
Building on a relationship that stretches back five years, we collaborated with Microsoft Azure Quantum at a very deep level to best execute their innovative qubit-virtualization system, including error diagnostics and correction. The Microsoft team was able to optimize their error correction innovation, reducing an original estimate of 300 required physical qubits 10-fold, to create four logical qubits with only 30 physical qubits, bringing it into scope for the 32-qubit H2 quantum computer.
This massive compression of the code and efficient virtualization challenges a consensus view about the resources needed to do fault-tolerant quantum computing, where it has been routinely stated that a logical qubit will require hundreds, even thousands of physical qubits. Through our collaboration, Microsoft’s far more efficient encoding was made possible by architectural features unique to the System Model H2, including our market-leading 99.8% two-qubit gate fidelity, 32 fully-connected qubits, and compatibility with Quantum Intermediate Representation (QIR).
Thanks to this powerful combination of collaboration, engineering excellence, and resource efficiency, quantum computing has taken a major step into a new era, introducing reliable logical qubits which will soon be available to industrial and research users.
Understanding today’s error correction breakthrough
It is widely recognized that for a quantum computer to be useful, it must be able to compute correctly even when errors (or faults) occur – this is what scientists and engineers describe as fault-tolerance.
In classical computing, fault-tolerance is well-understood and we have come to take it for granted. We always assume that our computers will be reliable and fault-free. Multiple advances over the course of decades have led to this state of affairs, including hardware that is incredibly robust and error rates that are very low, and classical error correction schemes that are based on the ability to copy information across multiple bits, to create redundancy.
Getting to the same point in quantum computing is more challenging, although the solution to this problem has been known for some time. Qubits are incredibly delicate since one must control the precise quantum states of single atoms, which are prone to errors. Additionally, we must abide by a fundamental law of quantum physics known as the no cloning theorem, which says that you can’t just copy qubits – meaning some of the techniques used in classical error correction are unavailable in quantum machines.
The solution involves entangling groups of physical qubits (thereby creating a logical qubit), storing the relevant quantum information in the entangled state, and, via some complex functions, performing computations with error correction. This process is all done with the sole purpose of creating logical qubit errors lower than the errors at the physical level.
However, implementing quantum error correction requires a significant number of qubit operations. Unless the underlying physical fidelity is good enough, implementing a quantum error correcting code will add more noise to your circuit than it takes away. No matter how clever you are in implementing a code, if your physical fidelity is poor, the error correcting code will only introduce more noise. But, once your physical fidelity is good enough (aka when the physical error rate is “below threshold”), then you will see the error correcting code start to actually help: producing logical errors below the physical errors.
Quantinuum’s fault-tolerance roadmap
Today’s results are an exciting marker on the path to fault-tolerant quantum computing. The focus must and will now shift from quantum computing companies simply stating the number of qubits they have to explaining their connectivity, the underlying quality of the qubits with reference to gate fidelities, and their approach to fault-tolerance.
Our H-Series hardware roadmap has not only focused on scaling qubits, but also developing useable quantum computers that are part of a vertically integrated stack. Our work across the full stack includes major advances at every level, for instance just last month we proved that our qubits could scale when we announced solutions to the wiring problem and the sorting problem. By maintaining higher qubit counts and world class fidelity, our customers and partners are able to advance further and faster in fields such as material science, drug discovery, AI and finance.
In 2025, we will introduce a new H-Series quantum computer, Helios, that takes the very best the H-Series has to offer, improving both physical qubit count and physical fidelity. This will take us and our users below threshold for a wider set of error correcting codes and make that device capable of supporting at least 10 highly reliable logical qubits.
A path to real-world impact
As we build upon today’s milestone and lead the field on the path to fault-tolerance, we are committed to continuing to make significant strides in the research that enables the rapid advance of our technologies. We were the first to demonstrate real-time quantum error correction (meaning a fully-fault tolerant QEC protocol), a result that meant we were the first to show: repeated real-time error correction, the ability to perform quantum "loops" (repeat-until-success protocols), and real-time decoding to determine the corrections during the computation. We were the first to create non-Abelian topological quantum matter and braid its anyons, leading to topological qubits.
The native flexibility of our QCCD architecture has allowed us to efficiently investigate a large variety of fault-tolerant methods, and our best-in-class fidelity means we expect to lead the way in achieving reduced error rates with additional error correcting codes – and supporting our partners to do the same. We are already working on making reliable quantum computing a commercial reality so that our customers and partners can unlock the enormous real-world economic value that is waiting to be unleashed by the development of these systems.
In the short term – with a hybrid supercomputer powered by a hundred reliable logical qubits, we believe that organizations will be able to start to see scientific advantages and will be able to accelerate valuable progress toward some of the most important problems that mankind faces such as modelling the materials used in batteries and hydrogen fuel cells or accelerating the development of meaning-aware AI language models. Over the long-term, if we are able to scale closer to ~1,000 reliable logical qubits, we will be able to unlock the commercial advantages that can ultimately transform the commercial world.
Quantinuum customers have always been able to operate the most cutting-edge quantum computing, and we look forward to seeing how they, and our own world-leading teams, drive ahead developing new solutions based on the state-of-the-art tools we continue to put into their hands. We were the early leaders in quantum computing and now we are thrilled to be positioned at the forefront of fault-tolerant quantum computing. We are excited to see what today’s milestone unlocks for our customers in the days ahead.
For more information
- Please register for Microsoft’s upcoming Quantum Innovator Series with Quantinuum
- Visit Quantinuum InQuanto to explore this state-of-the-art chemistry platform that will soon offer reliable logical qubits
- Read Microsoft’s announcement
- See System Model H1 and H2 integrated on Azure Quantum
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.
By: Harry Buhrman, Chief Scientist
Quantum computing is often framed as a race to the most qubits, the fastest gates, and the biggest benchmarks.
But a race needs a destination. In the fault-tolerant era, that means solving a valuable problem faster or at a lower cost than the best classical approach—and the time to solution is ultimately what matters most.
In this context, gate speed metrics have received a lot of attention. While gate speed is a meaningful component of the overall quality of a quantum computer, what actually matters most is fidelity. As we all know, speed on its own matters little if we don’t arrive at the correct destination.
Fidelity has emerged as the most important foundation for success in quantum computing. Higher fidelity means fewer errors in the underlying physical operations. Combined with quantum error correction, higher fidelity can reduce the number of additional qubits and operations needed to make computations reliable. This reduction in overhead can lower costs and shorten the time to deliver a useful answer—even compared with systems that have faster gates but lower fidelity.
Fast Gates Do Not Guarantee Fast Answers
Consider a simple example. In an independent-error model, a computation with 10,000 operations, each with an error rate of 10⁻³, or 99.9% fidelity, will experience about ten faults on average that can render the computation useless.
Now make every gate ten times faster without changing its error rate. You still get ten faults. You just get them ten times sooner.
Speed matters, but the relevant measure is the total time required to obtain a trustworthy and useful result. Getting to that point requires performance in many different and connected areas such as state preparation, measurement, error correction, repeated runs, and other work needed to complete the computation.
Gate speed alone cannot establish which system performs best. A fast machine that cannot reliably finish a sufficiently large computation cannot deliver commercial value.
Why Fidelity Changes the Resource Equation
Quantum error correction protects information by encoding it across multiple physical qubits. That protection requires resources: additional qubits, measurements, operations, and classical processing. These techniques work better when the underlying physical operations are reliable enough that increasing error protection reduces the logical error rate.
This requirement is known as the fault-tolerance threshold, the point below which physical error rates are low enough that adding protection reduces logical errors. Faster gates can shorten the computation, but they cannot replace the physical fidelity needed to cross that threshold.
At Quantinuum, our latest error-correction results on Helios demonstrate this principle. Using our error-correction architecture, logical memory errors fell exponentially as we increased protection. Across the tested code sizes, the fitted error reduction was about twelvefold for each increase of two in code distance. In the largest quantum-memory experiment, the estimated failure rate was about five in a million per error-correction cycle.1 This demonstrates how high-fidelity physical operations and effective error correction work together to make quantum information more reliable as protection grows.
The next question is what that reliability enables. How large a computation can a system complete, and how quickly can it deliver the result?
A New Performance Benchmark
The Quantum Universal Operations Performance System, or QUOPS, provides a standardized way to assess both. This architecture-neutral benchmark gauges performance by measuring computational “reach” and speed.2
“Reach” measures how large a benchmark circuit a system can execute successfully. Speed measures how quickly it executes that circuit, in effective quantum operations per second. QUOPS uses wall-clock time and accounts for extra samples and discarded runs caused by noise.
Together, these measures provide a common basis for comparing what different quantum systems deliver and tracking progress toward better time to solution.
Quantinuum’s H2 and Helios systems executed substantially larger benchmark circuits than Google’s Willow and IBM’s Boston. These superconducting systems sometimes achieved higher effective operation rates, but on smaller circuits, which means that they are not computationally comparable.
Superconducting systems can use error mitigation to tackle larger computations, but at a steep cost in speed. The QUOPS study estimates that the additional repetitions can make effective processing thousands of times slower. Some computations remain beyond the system’s reliable reach, even with mitigation. In those cases, faster gates may deliver no useful answer at all within practical limits on time and cost.
Useful applications require speed on much larger circuits. For example, the study estimates that factoring RSA-2048 or calculating FeMoco’s ground-state energy within five days would require roughly 100,000 times the computational reach demonstrated by today’s physical-qubit processors. Some machines approach the estimated speed requirement, but only on small circuits. The challenge is to sustain that speed at the required scale, including the additional work needed for error correction.
Larger uncorrected circuits accumulate more errors. Protecting them requires extra qubits and time. Reliability and speed must therefore scale together, and QUOPS offers a way to track both.
Higher Fidelity Makes Larger, Reliable Computations Possible
Improving fidelity can reduce the extra qubits and operations needed for error correction, lowering the time, cost, and resources required for useful computation. The benefit comes from reaching the required reliability with less protection, leaving more resources available for the computation itself.
Helios brings together the physical performance and error-correction capabilities needed to pursue those savings. In our paper published in Nature we showed that the system achieved an average single-qubit gate fidelity of 99.9975% and average two-qubit gate fidelity of 99.921% across its operational zones, while scaling the trapped-ion architecture to 98 fully connected physical qubits.3
The latest color-code experiments build on that physical performance. Alongside the logical memory results, protected two-qubit Clifford operations also became more reliable as protection increased. This connects improvements in the underlying hardware to improvements in logical computation.
A flexible error-correction architecture creates further opportunities to improve efficiency. Our recent Helix and color-code demonstrations used the same Helios hardware to explore different balances of accuracy and physical-qubit requirements. That flexibility allows us to evaluate which codes best suit different computational tasks as systems scale.
However, we continue to push ahead and accelerate the development of machines, such as Apollo, where quantum utility comes into play at scale. Decoding in the new color-code benchmarks was performed offline, and we are now turning our attention to integrating error correction, magic-state resources and real-time control into longer, reliable computations.
While that work continues, today’s systems can already contribute to scientific research. NISQ systems have advanced algorithms and hardware, enabled certified randomness, and supported studies of quantum magnetism and superconducting pairing correlations. These results leave room for useful applications before fault tolerance, even as error correction provides the scalable path to larger, reliable computations.4
The goal is to combine these capabilities so that larger computations can run reliably within practical limits on time and resources. Fidelity provides the foundation, and optimizing the full system turns that foundation into better time to solution.
Fidelity First. Then Optimize Time to Solution.
Scaling quantum computation requires continued progress in fidelity. As physical operations move further below threshold, increasing error protection can suppress logical errors more effectively, enabling longer, more demanding computations.
Speed must improve alongside that reliability. Advances in transport, cooling, measurement, compilation, and parallel execution can reduce the time and total cost of solving useful problems. These improvements become increasingly valuable as systems gain the reliability needed to complete larger computations.
Our latest Helios results are proof points on the path to Apollo, our planned universal fault-tolerant quantum computer, expected by 2029. The goal is to translate these gains into systems that can solve industrially relevant problems faster or at lower cost than the best classical approach.
Industrial partnerships help connect that progress to problems that matter, from understanding high-temperature superconductivity to how molecules interact to accelerate drug discovery. They bring practical research questions into the development process and help identify where improving quantum capabilities could deliver useful results beyond the reach of classical computing alone.
Our motto is simple: fidelity first, with speed built on that foundation.
References & For Further Reading
[1] A. Lavasani et al., "Quantum error correction well below the color code threshold," arXiv:2610.24077 [quant-ph] (2026). doi:10.48550/arXiv.2610.24077.
[2] T. Proctor et al., "Benchmarking the computational power of quantum computers," arXiv:2609.12146 [quant-ph] (2026). doi:10.48550/arXiv.2609.12146.
[3] A. Ransford et al., "A 98-qubit trapped-ion quantum computer with all-to-all connectivity," Nature 655, 81-86 (2026). doi:10.1038/s41586-026-10676-4.
[4] M. Liu, R. Shaydulin, P. Niroula et al., "Certified randomness using a trapped-ion quantum processor," Nature 640, 343-348 (2025). doi:10.1038/s41586-025-08737-1.
S. Dasu et al., "Computing with many encoded logical qubits beyond break-even," arXiv:2602.22211 [quant-ph] (2026). doi:10.48550/arXiv.2602.22211.
E. Granet et al., "Superconducting pairing correlations on a trapped-ion quantum computer," arXiv:2511.02125 [quant-ph] (2025; revised 2026). doi:10.48550/arXiv.2511.02125.
Quantinuum and GE Vernova’s Advanced Research Center are launching a collaboration to apply quantum computing to one of the research community’s most consequential challenges: understanding the behavior behind high-temperature superconductivity. Advances in this field could, over the long term, transform the energy sector by enabling lighter generators, more compact and powerful motors, and electricity infrastructure that carries more power and better withstands faults.
The research will focus on Fermi–Hubbard modeling, a framework for studying how interacting electrons give rise to complex material properties. By combining Quantinuum’s full-stack quantum computing capabilities—including access to the company’s Helios computer—with GE Vernova’s expertise in material science and engineering simulation applied to industrial applications, the collaboration will bring an industry perspective to a promising area of quantum research.
Why superconductors matter for energy
As energy systems grow, the size, weight, and performance of electrical equipment become increasingly important constraints. High-temperature superconductors offer potential ways to address those limits through their ability to carry large electrical currents without resistance under suitable operating conditions.
Potential applications span power generation, electricity grids, and industrial electrification. Superconducting generators could reduce the weight and footprint of industrial equipment. Superconducting windings could also help make utility generators and industrial or marine propulsion motors more compact and efficient. In electricity networks, superconducting cables could carry more power through constrained spaces, while fault current limiters could help protect equipment during short circuits.
Realizing those benefits more widely depends on overcoming challenges in cooling, material performance, manufacturing, and cost. Better understanding of the physics behind high-temperature superconductivity could help inform the search for materials with more practical operating characteristics.
Why quantum computing may offer new tools for understanding high-temperature superconductivity
High-temperature superconductivity involves the collective behavior of strongly interacting electrons. Accurately modeling these systems is exceptionally difficult: the interactions that make them scientifically interesting also make important aspects of their behavior computationally challenging.
The Fermi–Hubbard model captures essential features of those interactions in a simplified mathematical framework. Although it is not a complete description of a material used in industrial applications, it provides a foundation for investigating mechanisms associated with high-temperature superconductivity.
Quantum computing offers a promising way to explore the physics. Quantinuum researchers have already measured superconducting pairing correlations—including s-wave and d-wave pairing—in Fermi–Hubbard models simulated on the Helios quantum computer. These results demonstrate the ability to prepare and probe quantum states relevant to superconductivity research, establishing a foundation for further investigation.
The collaboration with GE Vernova will build on that foundation, bringing industrial expertise to the selection and interpretation of research questions.
Connecting quantum capabilities with industrial expertise
The research will be enabled through access to Quantinuum’s full-stack capabilities, including cloud-based access to Helios, the world’s most accurate quantum computer1, and Nexus, Quantinuum’s developer platform. Nexus connects quantum hardware with the software tools researchers need to develop and run applications in a unified environment.
GE Vernova’s Advanced Research Center brings the expertise in material science, engineering, and industrial applications to the research and development activity.
“High-temperature superconductors could help us overcome important limits on the size, weight, and efficiency of electrical equipment, but understanding and improving these materials remains a significant scientific challenge,” said Jonathan Owens, PhD, Senior Scientist, Computational Materials Physics at GE Vernova. “By combining our materials simulation and industrial expertise with Quantinuum’s quantum computing capabilities, we can explore new approaches to these difficult problems while building the expertise to assess where quantum computing can make a meaningful contribution.”
The collaboration also extends GE Vernova’s exploration of quantum computing into a new area of materials research while supporting the development of its internal quantum talent. Its previous published work includes investigations of quantum algorithms for carbon-capture materials using simulated quantum processors.
Building toward industrial value
Translating insights from simplified models into practical materials requires sustained scientific and engineering work. Industrial expertise helps connect that effort to the properties, operating conditions, and manufacturing considerations that ultimately determine a material’s usefulness.
For Quantinuum, this collaboration is an opportunity to advance quantum simulation with an industrial collaborator that understands both the potential applications and the barriers to adoption. It brings together demonstrated computing capabilities, a challenging materials problem, and the expertise needed to connect scientific progress with industrial requirements.
The research collaboration aims to deepen understanding of this field and explore how quantum computing may contribute to future energy technologies.
1 Based on two-qubit gate fidelity as of December 31, 2025.
From Oracle's Quantum AI Compute beta program to upcoming Helios installation milestones and Oracle AI World, our partnership continues to gain momentum.
When Quantinuum and Oracle announced a strategic partnership earlier this year, the goal was not simply to deploy a quantum computer in the cloud. It was to create a practical path for bringing quantum computing into the enterprise environments where AI, data, and high-performance computing (HPC) already come together.
By combining Oracle Cloud Infrastructure (OCI)'s AI, data, and cloud capabilities with Helios, Quantinuum's most advanced quantum computer, we're helping lay the foundation for hybrid quantum AI computing at enterprise scale. The partnership reflects our belief that some of the most valuable future applications will emerge when quantum computing, AI and classical HPC work together to tackle problems that remain difficult to solve today.
Oracle Opens Early Access for Quantum AI Compute
That vision is now being put into practice. This month, Oracle launched the OCI Quantum AI Compute Beta Program, giving select organizations an opportunity to begin evaluating how quantum computing fits into existing workflows and computational challenges.
Through the program, approved participants will gain cloud-based access to Helios, the world's most accurate commercial quantum computer, alongside OCI's GPU and HPC infrastructure. For organizations exploring quantum computing, this creates a practical starting point: access to industry-leading hardware within an enterprise cloud environment, without the need to build specialized infrastructure of their own.
The goal is to help organizations understand where hybrid quantum AI workflows may create value across areas such as drug discovery, materials science, energy, financial modeling, and optimization.
For many organizations, the starting point is not quantum technology itself. It's a business or research problem. Where are today's approaches reaching meaningful limits? Which workloads consume disproportionate resources? And where could a new computational capability create an advantage?
Organizations interested in participating can apply through Oracle's OCI Preview Programs portal. Oracle will review applications and select participants based on eligibility, capacity and program requirements.
Quantinuum and Oracle Leadership Takes the Stage at Oracle AI World
The opportunity for hybrid quantum-AI computing will be a major topic at Oracle AI World 2026.
In a main stage session, "Powering the Next Era of Enterprise AI," Larry Stack, Chief Commercial Officer at Quantinuum, will join Mahesh Thiagarajan, Executive Vice President and Head of Oracle Cloud Infrastructure, to discuss how quantum computing, AI and classical HPC can work together to address some of the world's most computationally demanding challenges.
The discussion will focus on a core question many organizations are asking: where should they start? Rather than leading with technology, the conversation will explore how organizations can identify high-value problems, establish today's performance baseline, and evaluate where quantum computing ultimately provides an advantage.
Later in the day, Quantinuum and Oracle experts will take a deeper look at how bringing Helios into OCI provides managed access to quantum computing natively within an enterprise cloud environment to support hybrid quantum-AI workflows.
Building Momentum Toward Hybrid Quantum-AI Computing
The collaboration between Quantinuum and Oracle continues to progress from vision to execution.
With Helios advancing toward installation, Oracle's Quantum AI Compute program now open for early access, and enterprise interest growing around hybrid computing, the pieces are coming together. Organizations now have a practical way to begin exploring quantum computing through cloud-based access to Helios alongside AI, HPC, and existing enterprise workflows.
We look forward to continuing the conversation at Oracle AI World 2026 and working with customers who want to better understand where hybrid quantum-AI computing can create real-world value.
We're excited to continue that conversation at Oracle AI World 2026 and to help customers begin exploring what's possible through the OCI Quantum AI Compute Beta Program.