Demonstrating Benefits of Quantum Upgradable Design Strategy
System Model H1-2 First to Prove 2,048 Quantum Volume
Quantinuum’s H-Series quantum computers, Powered by Honeywell, continue to deliver on exponential performance gains
Over the course of 2021, Quantinuum’s customers and collaborators were the beneficiaries of a deliberate, strategic approach to quantum computing design. Namely, that it is possible to release a generation of quantum computers that can be quickly and systematically upgraded in parallel with commercial usage, allowing customers immediate access to the latest upgrades.
With the release of the System Model H1, Powered by Honeywell, in fall 2020, Quantinuum began a real-time demonstration of its design approach. The first System Model H1, referred to as the H1-1, launched in October 2020 with a measured quantum volume of 128. Quantum volume is a metric introduced by IBM to measure the overall capability and performance of a quantum computing system regardless of technology. (Calculating quantum volume requires running a series of complex random circuits and performing a statistical test on the results.)
During 2021, Quantinuum, under its trapped-ion hardware group, previously known as Honeywell Quantum Solutions, made multiple upgrades to the H1-1 achieving measured quantum volume records of 512 in March 2021 and the 1,024 in July 2021. During that same period, Quantinuum was quietly releasing its second H1 generation quantum computer to customers and collaborators, called the H1-2. The System Model H1-2 uses the same ion-trap architecture, control system design, integrated optics, and photonics as the H1-1.
“Our H1 generation of quantum computers are nearly identical copies, with the ongoing exception that at any given time one computer might have received upgrades prior to the other,” said Dr. Russ Stutz, Head of Commercial Products for the hardware team. “Our goal is to provide users with the highest performing hardware as they work on solving real world problems."
Upgrades to both H1 quantum computers over the course of 2021 included improved gate and measurement fidelities, reduced memory errors, faster circuit compilation, inclusion of real-time classical computing resources and quantum operations using 12 qubits, versus the 10 qubits available at initial release.
What has been remarkable about the approach, is the ability to deliver near-continuous capability upgrades while being consistent on performance.
“Our customers frequently comment about their ability to reliably get expected results, including when running deep circuits and using sophisticated features like mid-circuit measurement, qubit reuse and conditional logic,” said Dr. Brian Neyenhuis, Head of Commercial Operations for the hardware team.
Just this past week, H1-2 measured a Quantum Volume of 2,048 (211), setting a new bar on the highest quantum volume ever measured on a quantum computer. The performance of the H1 generation of quantum computers continues to achieve the 10X per year increase that was announced in March 2020.
The Data
The average single-qubit gate fidelity for this milestone was 99.996(2)%, the average two-qubit gate fidelity was 99.77(9)%, and state preparation and measurement (SPAM) fidelity was 99.61(2)%. We ran 2,000 randomly generated quantum volume circuits with 5 shots each, using standard optimization techniques to yield an average of 122 two-qubit gates per circuit.
The System Model H1-2 successfully passed the quantum volume 2,048 benchmark, returning heavy outputs 69.76% of the time, which is above the 2/3 threshold with 99.87% confidence.
The plot above shows the heavy outputs for Quantinuum’s tests of quantum volume and the dates when each test passed. All tests are above the 2/3 threshold to pass the respective quantum volume benchmark. Circles indicate heavy output averages and the violin plots show the histogram distributions. Data colored in blue show system performance results and red points correspond to modeled, noise-included simulation data. White markers are the lower two-sigma error bounds.
The plot above shows the individual heavy outputs for each quantum volume 2,048 circuit. The blue line is an average of heavy outputs and the orange line is the lower two-sigma error bar which crosses the 2/3 threshold after 818 circuits, which corresponds to passing.
This is the latest in a string of accomplishments for Quantinuum, which recently announced the completion of its combination between Honeywell Quantum Solutions and Cambridge Quantum Computing to form the largest stand-alone integrated quantum computing company in the world. This news also falls on the heels of the release of Quantinuum’s flagship product, Quantum Origin, the world’s first quantum-enhanced cryptographic key generation platform.
“We look forward to continued momentum in 2022 with expected advances in multiple application areas as well as further advances in the H-Series quantum computers”, said Tony Uttley, President and Chief Operating Officer of Quantinuum.
* The Honeywell trademark is used under license from Honeywell International Inc. Honeywell makes no representations or warranties with respect to this product or 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.
If we are to create ‘next-gen’ AI that takes full advantage of the power of quantum computers, we need to start with quantum native transformers. Today we announce yet again that Quantinuum continues to lead by demonstrating concrete progress — advancing from theoretical models to real quantum deployment.
The future of AI won't be built on yesterday’s tech. If we're serious about creating next-generation AI that unlocks the full promise of quantum computing, then we must build quantum-native models—designed for quantum, from the ground up.
Around this time last year, we introduced Quixer, a state-of-the-art quantum-native transformer. Today, we’re thrilled to announce a major milestone: one year on, Quixer is now running natively on quantum hardware.
Why this matters: Quantum AI, born native
This marks a turning point for the industry: realizing quantum-native AI opens a world of possibilities.
Classical transformers revolutionized AI. They power everything from ChatGPT to real-time translation, computer vision, drug discovery, and algorithmic trading. Now, Quixer sets the stage for a similar leap — but for quantum-native computation. Because quantum computers differ fundamentally from classical computers, we expect a whole new host of valuable applications to emerge.
Achieving that future requires models that are efficient, scalable, and actually run on today’s quantum hardware.
That’s what we’ve built.
What makes Quixer different?
Until Quixer, quantum transformers were the result of a brute force “copy-paste” approach: taking the math from a classical model and putting it onto a quantum circuit. However, this approach does not account for the considerable differences between quantum and classical architectures, leading to substantial resource requirements.
Quixer is different: it’s not a translation – it's an innovation.
With Quixer, our team introduced an explicitly quantum transformer, built from the ground up using quantum algorithmic primitives. Because Quixer is tailored for quantum circuits, it's more resource efficient than most competing approaches.
As quantum computing advances toward fault tolerance, Quixer is built to scale with it.
What’s next for Quixer?
We’ve already deployed Quixer on real-world data: genomic sequence analysis, a high-impact classification task in biotech. We're happy to report that its performance is already approaching that of classical models, even in this first implementation.
This is just the beginning.
Looking ahead, we’ll explore using Quixer anywhere classical transformers have proven to be useful; such as language modeling, image classification, quantum chemistry, and beyond. More excitingly, we expect use cases to emerge that are quantum-specific, impossible on classical hardware.
This milestone isn’t just about one model. It’s a signal that the quantum AI era has begun, and that Quantinuum is leading the charge with real results, not empty hype.
Stay tuned. The revolution is only getting started.
Our team is participating in ISC High Performance 2025 (ISC 2025) from June 10-13 in Hamburg, Germany!
As quantum computing accelerates, so does the urgency to integrate its capabilities into today’s high-performance computing (HPC) and AI environments. At ISC 2025, meet the Quantinuum team to learn how the highest performing quantum systems on the market, combined with advanced software and powerful collaborations, are helping organizations take the next step in their compute strategy.
Quantinuum is leading the industry across every major vector: performance, hybrid integration, scientific innovation, global collaboration and ease of access.
- Our industry-leading quantum computer holds the record for performance with a Quantum Volume of 2²³ = 8,388,608 and the highest fidelity on a commercially available QPU available to our users every time they access our systems.
- Our systems have been validated by a #1 ranking against competitors in a recent benchmarking study by Jülich Research Centre.
- We’ve laid out a clear roadmap to reach universal, fully fault-tolerant quantum computing by the end of the decade and will launch our next-generation system, Helios, later this year.
- We are advancing real-world hybrid compute with partners such as RIKEN, NVIDIA, SoftBank, STFC Hartree Center and are pioneering applications such as our own GenQAI framework.
Exhibit Hall
From June 10–13, in Hamburg, Germany, visit us at Booth B40 in the Exhibition Hall or attend one of our technical talks to explore how our quantum technologies are pushing the boundaries of what’s possible across HPC.
Presentations & Demos
Throughout ISC, our team will present on the most important topics in HPC and quantum computing integration—from near-term hybrid use cases to hardware innovations and future roadmaps.
Multicore World Networking Event
- Monday, June 9 | 7:00pm – 9:00 PM at Hofbräu Wirtshaus Esplanade
In partnership with Multicore World, join us for a Quantinuum-sponsored Happy Hour to explore the present and future of quantum computing with Quantinuum CCO, Dr. Nash Palaniswamy, and network with our team.
Register here
H1 x CUDA-Q Demonstration
- All Week at Booth B40
We’re showcasing a live demonstration of NVIDIA’s CUDA-Q platform running on Quantinuum’s industry-leading quantum hardware. This new integration paves the way for hybrid compute solutions in optimization, AI, and chemistry.
Register for a demo
HPC Solutions Forum
- Wednesday, June 11 | 2:20 – 2:40 PM
“Enabling Scientific Discovery with Generative Quantum AI” – Presented by Maud Einhorn, Technical Account Executive at Quantinuum, discover how hybrid quantum-classical workflows are powering novel use cases in scientific discovery.
See You There!
Whether you're exploring hybrid solutions today or planning for large-scale quantum deployment tomorrow, ISC 2025 is the place to begin the conversation.
We look forward to seeing you in Hamburg!
Quantinuum has once again raised the bar—setting a record in teleportation, and advancing our leadership in the race toward universal fault-tolerant quantum computing.
Last year, we published a paper in Science demonstrating the first-ever fault-tolerant teleportation of a logical qubit. At the time, we outlined how crucial teleportation is to realize large-scale fault tolerant quantum computers. Given the high degree of system performance and capabilities required to run the protocol (e.g., multiple qubits, high-fidelity state-preparation, entangling operations, mid-circuit measurement, etc.), teleportation is recognized as an excellent measure of system maturity.
Today we’re building on last year’s breakthrough, having recently achieved a record logical teleportation fidelity of 99.82% – up from 97.5% in last year’s result. What’s more, our logical qubit teleportation fidelity now exceeds our physical qubit teleportation fidelity, passing the break-even point that establishes our H2 system as the gold standard for complex quantum operations.
This progress reflects the strength and flexibility of our Quantum Charge Coupled Device (QCCD) architecture. The native high fidelity of our QCCD architecture enables us to perform highly complex demonstrations like this that nobody else has yet to match. Further, our ability to perform conditional logic and real-time decoding was crucial for implementing the Steane error correction code used in this work, and our all-to-all connectivity was essential for performing the high-fidelity transversal gates that drove the protocol.
Teleportation schemes like this allow us to “trade space for time,” meaning that we can do quantum error correction more quickly, reducing our time to solution. Additionally, teleportation enables long-range communication during logical computation, which translates to higher connectivity in logical algorithms, improving computational power.
This demonstration underscores our ongoing commitment to reducing logical error rates, which is critical for realizing the promise of quantum computing. Quantinuum continues to lead in quantum hardware performance, algorithms, and error correction—and we’ll extend our leadership come the launch of our next generation system, Helios, in just a matter of months.