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Discover how we are pushing the boundaries in the world of quantum computing

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technical
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June 12, 2024
We’ve just found a new, resource-efficient way to set up calculations

A key step in many quantum algorithms is setting everything up: you need all your dominoes in place before you can do much else. This is called “state preparation”, and it’s a trickier problem than it might seem. 

Our team has developed new protocols that can help – and in a big way. Specifically, the team worked on preparing “multivariate” functions, which just means functions that are used to explore problems with more than one variable, or in more than 1 dimension. One-dimensional problems do exist (think of a path that only goes forwards or backwards – we can call the variable “x”) but in the real world it’s much more common to have problems with many dimensions, or variables (think instead of a landscape where you can go forwards, backwards, left, right, up, and down – we can call the variables “x”, ”y”, and “z”).

Our new multivariate function quantum state preparation protocols don’t rely on some commonly-used and computationally expensive subroutines - instead they expand the desired multivariate function into well-known mathematical basis functions, called Fourier and Chebyshev functions. This makes our protocols simpler and more effective than previous options. 

Generally, state preparation is a hard problem, and costs exponentially many resources to prepare an arbitrary state. By expanding the functions in a Fourier or Chebyshev series, one can truncate the series to create good approximations, which instead uses only polynomially many resources – meaning that this method has better asymptotic scaling than many other non-heuristic methods (which are often designed to work in only one dimension anyways). 

Our team used their protocol to prepare a commonly used initial state on our H2 trapped-ion quantum processor, the bivariate Gaussian. Bivariate Gaussians are used everywhere from physics to finance, underscoring the practicality of these new protocols. They also analyzed examples potentially useful for quantum chemistry and partial differential equations.

A very nice feature of this work is that it is broadly applicable, generic, and entirely modular – meaning it can be plugged in to the beginning of almost any quantum algorithm, giving our customers and users even more flexibility and power. 

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June 5, 2024
Quantinuum’s H-Series hits 56 physical qubits that are all-to-all connected, and departs the era of classical simulation

The first half of 2024 will go down as the period when we shed the last vestiges of the “wait and see” culture that has dominated the quantum computing industry. Thanks to a run of recent achievements, we have helped to lead the entire quantum computing industry into a new, post-classical era.

Today we are announcing the latest of these achievements: a major qubit count enhancement to our flagship System Model H2 quantum computer from 32 to 56 qubits. We also reveal meaningful results of work with our partner JPMorgan Chase & Co. that showcases a significant lift in performance.

But to understand the full importance of today’s announcements, it is worth recapping the succession of breakthroughs that confirm that we are entering a new era of quantum computing in which classical simulation will be infeasible.

A historic run

Between January and June 2024, Quantinuum’s pioneering teams published a succession of results that accelerate our path to universal fault-tolerant quantum computing. 

Our technical teams first presented a long-sought solution to the “wiring problem”, an engineering challenge that affects all types of quantum computers. In short, most current designs will require an impossible number of wires connected to the quantum processor to scale to large qubit numbers. Our solution allows us to scale to high qubit numbers with no issues, proving that our QCCD architecture has the potential to scale.

Next, we became the first quantum computing company in the world to hit “three 9s” two qubit gate fidelity across all qubit pairs in a production device. This level of fidelity in 2-qubit gate operations was long thought to herald the point at which error corrected quantum computing could become a reality. It has accelerated and intensified our focus on quantum error correction (QEC). Our scientists and engineers are working with our customers and partners to achieve multiple breakthroughs in QEC in the coming months, many of which will be incorporated into products such as the H-Series and our chemistry simulation platform, InQuanto™.

Following that, with our long-time partner Microsoft, we hit an error correction performance threshold that many believed was still years away. The System Model H2 became the first – and only – quantum computer in the world capable of creating and computing with highly reliable logical (error corrected) qubits. In this demonstration, the H2-1 configured with 32 physical qubits supported the creation of four highly reliable logical qubits operating at “better than break-even”. In the same demonstration, we also shared that logical circuit error rates were shown to be up to 800x lower than the corresponding physical circuit error rates. No other quantum computing company is even close to matching this achievement (despite many feverish claims in the past 12 months).

Pushing to the limits of supercomputing … and beyond

The quantum computing industry is departing the era when quantum computers could be simulated by a classical computer. Today, we are making two milestone announcements. The first is that our H2-1 processor has been upgraded to 56 trapped-ion qubits, making it impossible to classically simulate, without any loss of the market-leading fidelity, all-to-all qubit connectivity, mid-circuit measurement, qubit reuse, and feed forward.

The second is that the upgrade of H2-1 from 32 to 56 qubits makes our processor capable of challenging the world’s most powerful supercomputers. This demonstration was achieved in partnership with our long-term collaborator JPMorgan Chase & Co. and researchers from Caltech and Argonne National Lab.

Our collaboration tackled a well-known algorithm, Random Circuit Sampling (RCS), and measured the quality of our results with a suite of tests including the linear cross entropy benchmark (XEB) – an approach first made famous by Google in 2019 in a bid to demonstrate “quantum supremacy”. An XEB score close to 0 says your results are noisy – and do not utilize the full potential of quantum computing. In contrast, the closer an XEB score is to 1, the more your results demonstrate the power of quantum computing. The results on H2-1 are excellent, revealing, and worth exploring in a little detail. Here is the complete data on GitHub.

Better qubits, better results

Our results show how far quantum hardware has come since Google’s initial demonstration. They originally ran circuits on 53 superconducting qubits that were deep enough to severely frustrate high-fidelity classical simulation at the time, achieving an estimated XEB score of ~0.002. While they showed that this small value was statistically inconsistent with zero, improvements in classical algorithms and hardware have steadily increased what XEB scores are achievable by classical computers, to the point that classical computers can now achieve scores similar to Google’s on their original circuits.

Figure 1. At N=56 qubits, the H2 quantum computer achieves over 100x higher fidelity on computationally hard circuits compared to earlier superconducting experiments. This means orders of magnitude fewer shots are required for high confidence in the fidelity, resulting in comparable total runtimes

In contrast, we have been able to run circuits on all 56 qubits in H2-1 that are deep enough to challenge high-fidelity classical simulation while achieving an estimated XEB score of ~0.35. This >100x improvement implies the following: even for circuits large and complex enough to frustrate all known classical simulation methods, the H2 quantum computer produces results without making even a single error about 35% of the time. In contrast to past announcements associated with XEB experiments, 35% is a significant step towards the idealized 100% fidelity limit in which the computational advantage of quantum computers is clearly in sight.

This huge jump in quality is made possible by Quantinuum’s market-leading high fidelity and also our unique all-to-all connectivity. Our flexible connectivity, enabled by our QCCD architecture, enables us to implement circuits with much more complex geometries than the 2D geometries supported by superconducting-based quantum computers. This specific advantage means our quantum circuits become difficult to simulate classically with significantly fewer operations (or gates). These capabilities have an enormous impact on how our computational power scales as we add more qubits: since noisy quantum computers can only run a limited number of gates before returning unusable results, needing to run fewer gates ultimately translates into solving complex tasks with consistent and dependable accuracy.

This is a vitally important moment for companies and governments watching this space and deciding when to invest in quantum: these results underscore both the performance capabilities and the rapid rate of improvement of our processors, especially the System Model H2, as a prime candidate for achieving near-term value.

So what of the comparison between the H2-1 results and a classical supercomputer? 

A direct comparison can be made between the time it took H2-1 to perform RCS and the time it took a classical supercomputer. However, classical simulations of RCS can be made faster by building a larger supercomputer (or by distributing the workload across many existing supercomputers). A more robust comparison is to consider the amount of energy that must be expended to perform RCS on either H2-1 or on classical computing hardware, which ultimately controls the real cost of performing RCS. An analysis based on the most efficient known classical algorithm for RCS and the power consumption of leading supercomputers indicates that H2-1 can perform RCS at 56 qubits with an estimated 30,000x reduction in power consumption. These early results should be seen as very attractive for data center owners and supercomputing facilities looking to add quantum computers as “accelerators” for their users. 

Where we go next

Today’s milestone announcements are clear evidence that the H2-1 quantum processor can perform computational tasks with far greater efficiency than classical computers. They underpin the expectation that as our quantum computers scale beyond today’s 56 qubits to hundreds, thousands, and eventually millions of high-quality qubits, classical supercomputers will quickly fall behind. Quantinuum’s quantum computers are likely to become the device of choice as scrutiny continues to grow of the power consumption of classical computers applied to highly intensive workloads such as simulating molecules and material structures – tasks that are widely expected to be amenable to a speedup using quantum computers.

With this upgrade in our qubit count to 56, we will no longer be offering a commercial “fully encompassing” emulator – a mathematically exact simulation of our H2-1 quantum processor is now impossible, as it would take up the entire memory of the world’s best supercomputers. With 56 qubits, the only way to get exact results is to run on the actual hardware, a trend the leaders in this field have already embraced.

More generally, this work demonstrates that connectivity, fidelity, and speed are all interconnected when measuring the power of a quantum computer. Our competitive edge will persist in the long run; as we move to running more algorithms at the logical level, connectivity and fidelity will continue to play a crucial role in performance.

“We are entirely focused on the path to universal fault tolerant quantum computers. This objective has not changed, but what has changed in the past few months is clear evidence of the advances that have been made possible due to the work and the investment that has been made over many, many years. These results show that whilst the full benefits of fault tolerant quantum computers have not changed in nature, they may be reachable earlier than was originally expected, and crucially, that along the way, there will be tangible benefits to our customers in their day-to-day operations as quantum computers start to perform in ways that are not classically simulatable. We have an exciting few months ahead of us as we unveil some of the applications that will start to matter in this context with our partners across a number of sectors.”
– Ilyas Khan, Chief Product Officer

Stay tuned for results in error correction, physics, chemistry and more on our new 56-qubit processor.

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May 30, 2024
Join us at DAMOP to discover how Quantinuum is advancing quantum computing

The 55th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics (DAMOP) from June 3-7, 2024, will feature presentations from Quantinuum’s physicists working on the world’s leading quantum computing hardware.

Our team members will cover various topics including quantum computation, scaling quantum technologies with ion-trap, and progress across various fields within atomic, molecular, and optical physics

Meet our quantum computing experts at Table 39, from June 4th – 6th to discuss what’s new and what’s next in trapped-ion quantum computing.

Join these sessions to discover how Quantinuum is advancing quantum computing:

Path to Scale QCCD Architecture for Trapped Ion Quantum Computers
Speaker: Patty Lee, Chief Scientist for Hardware Technology Development
Date and Time: June 3, 2:30 pm – 3:45 pm
Location: Room 202AB

Scalable Multispecies Ion Transport in a Grid-Based Surface-Electrode Trap
Speaker: Robert Delaney, Advanced Physicist
Date and Time: June 4, 10:45 am – 12:45 pm
Location: Room 203B

Benchmarking Quantinuum’s Second-Generation Quantum Processor
Speaker: Julia Cline, Advanced Physicist
Date and Time: June 4, 2:00 pm – 4:00 pm
Location: Room 203A

A fast and robust cooling method for trapped-ion qubits: phonon rapid adiabatic passage (Poster Session I)
Presenter: Ivaylo Madjarov, Numerical Physicist
Date and Time: June 4, 4:00 pm – 6:00 pm
Location: Hall BC

Laser Cooling Trapped-Ion Crystal Modes Beyond the Lamb-Dicke Regime
Speaker: Chris Gilbreth, Lead Physicist
Date and Time: June 7, 11:30 am – 11:42 am
Location: Room 201BC

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May 8, 2024
Join Quantinuum at ISC24 to discuss integrating quantum computing into your existing compute infrastructure

With the rapid evolution of Quantum Computing, users are contemplating the best way to begin to integrate Quantum capabilities into their existing HPC and AI infrastructure. Find our experts at the ISC conference, May 12th-16th, in Hamburg, Germany to discuss our world leading hardware, applications, and case studies. 

Exhibit Hall

Drop by Booth K50 in the exhibit hall to meet tour team and see a display of our System Model H2 chip, Powered by Honeywell. 

If you’d like to schedule a 1:1 meeting, send us an email to schedule a time to meet. We have reserved meeting room Hall 5 at ISC, but we’d be happy to set up time to meet with you at or after the event.

Presentations

Our team will be presenting on a range of topics about integrating quantum computing into existing HPC infrastructure. They’ll be speaking about our hardware features and how you can leverage quantum computing with your existing HPC cluster.

May 13th

2:30pm – 3:00pm | Hall 4, ground level in the First-Time Exhibitor Pitch

Understanding Opportunities with Quantum Computing: Learn about our roadmap and key strategies to accelerate your current HPC clusters with the integration of quantum computing. 

Presented by Nash Palaniswamy, Chief Commercial Officer, Quantinuum

May 14th

2:00pm – 2:30pm | GENCI Booth K40

Simulation of Transition Metal Oxide (TMO) Atomic Layer Deposition (ALD): A Study of the modelling of electronic energies used in the reactions involved for ALD of ZrO2 and of the reactivity of organometallic precursors used in ALD technology for controlling the quality of thin film deposition on different substrates. The study is a collaboration between C12 Quantum Electronics, Air Liquide and Quantinuum, with support from PAQ Ile de France.

Presented by Maud Einhorn, Technical Account Manager, and Gabriela Cimpan, Partner Manager, Quantinuum

May 14th

2:20pm – 2:35pm | Hall Z – 3rd floor

The Trapped-Ion Quantum Processors at Quantinuum: Quantinuum has constructed two generations of QCCD (quantum charge-coupled device) quantum processors. These processors use trapped-ions for qubits and sympathetic cooling, and shuttling operations to achieve high-fidelity gating operations on individual qubits and between any pair of qubits – making them fully-connected. In this talk, Dave will discuss Quantinuum’s efforts to rigorously benchmark the performance of these machines, highlighting their strengths and weaknesses. He’ll also give a brief survey of our efforts toward near-term quantum advantage and quantum error correction. Finally, he’ll sketch out some technological developments aimed at scaling these processors and the implications for future devices.

Presented by David Hayes, Sr. R&D Manager for Theory and Architecture

May 14th and May 15th

12:30pm – 1:00pm | Meeting Room Hall 5

3:30pm – 4:00pm | Meeting Room Hall 5

Quantum Computing, Error Correction, and Scaling for the Future at Quantinuum: Quantum computing promises to provide significant computational savings in valuable problems such as chemistry, materials, and cybersecurity. To make this a reality, errors in quantum operations must be suppressed significantly below where they are today, and the size of quantum computing hardware must be increased. Quantinuum has recently made significant strides in scaling to larger sizes. Join the session to hear about these exciting results, our plans to scale, and a look towards the future.

Presented by Chris Langer, Fellow and Chairman of the Technical Board, Quantinuum

May 16th 

1:00pm – 1:20pm | Hall H, Booth L01 in the HPC Solutions Forum

Harnessing the potential of quantum computing: As the landscape of quantum computing continues to rapidly evolve, the question of when to invest in quantum computing knowledge remains a key strategic consideration for organizations. This talk will explore the challenge of quantum readiness by surveying some of the research collaborations Quantinuum has performed with a range of industry-leading organizations. Using real-world case studies, we will highlight the diverse array of sectors poised to benefit from early quantum adoption, including pharmaceuticals, finance, logistics, and cybersecurity. This talk begins to unpack why many first mover enterprise organizations have made significant investments in quantum readiness already, rather than deferring until the technology matures further. 

Presented by Maud Einhorn, Technical Account Manager, Quantinuum

May 16th

4:30pm – 5:00pm | Hall Y1 - 2nd floor

Workshop on Benchmarking and Scaling the Quantum Charged Coupled Device Quantum Computing architecture in the Quantum and Hybrid Quantum-Classical Computing Approaches: The QCCD architecture provides a unique approach to quantum computing where qubits are mobile and operating zones are fixed. In contrast to QC architectures where qubit and couplings between them are fixed, the QCCD architecture naturally provides all-to-all connectivity and high-fidelity operations. Additional advanced features include mid-circuit measurement, qubit reset, conditional logic, and variable angle gates. The talk will present benchmarking of our machines and recent progress towards scaling to larger systems.

Presented by Chris Langer, Fellow and Chair of the Technical Board, Quantinuum

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April 25, 2024
Theoretical work finds shortcut to solving the Max-Cut problem with a quantum computer

We are surrounded by optimization problems – for example, what’s the most efficient route for getting all your chores done on a Sunday? What’s the best way to pack a suitcase? Modern businesses can’t escape the importance of optimization problems, they’re critical in everything from charting shipping routes to setting prices. 

To solve such real-world examples, experts build mathematical models and explore computer algorithms capable of finding the optimal path through a problem. In many cases, as they scale, problems become intractable to even the most powerful classical supercomputers. Research suggests that for some problems, quantum algorithms offer some new promise. Our researchers have explored a quantum approach to a widely applicable optimization problem called “Max-Cut”, where one cuts a graph to snip as many vertices as possible.

Finding exact solutions to the Max-Cut problem in a reasonable amount of time would have practical applications in a wide range of situations, including supply chain management, machine scheduling, image recognition, quality control, fraud detection, patient diagnostics, and electric circuit design. For a generic graph, this problem is really hard: a computer scientist would call it “NP hard”. There is no known classical algorithm to solve Max-Cut for a generic graph whose runtime is polynomial in the number of vertices L, and it is strongly believed that no such classical algorithm exists. Many other useful optimization problems have a similar problem: they may simply be too expensive to solve exactly with classical computers. Back in the real world, this explains why many aspects of daily life run sub-optimally. Consider the experience of multiple drivers delivering a succession of small goods from the same vendor, often packaged in clearly oversized boxes. The costs of this sort of inefficiency accrue in terms of time, money, and environmental impact, locally and at the full scale of the global economy.

Our team has been working on applying a quantum solution to the Max-Cut problem based on the adiabatic theorem of quantum mechanics. Using the adiabatic theorem to solve an optimization problem involves encoding the problem into the qubits (setting up the Hamiltonian), then letting the system slowly evolve some parameter, carefully keeping it in the ground state the whole time. This method is an all-purpose solver for classically hard optimization problems, but it comes at a large computational cost: the “slow” evolution means applying lots of expensive gates to perform the many time steps needed. 

Our team figured out that instead of taking many expensive steps they could instead take a limited amount without destroying the convergence, as long as the optimization problem has a classical Hamiltonian. They call this “Floquet adiabatic evolution” and find that this approach reduces the required number of gates by several orders of magnitude.

Contrary to variational quantum algorithms such as Quantum Approximate Optimization Algorithm (QAOA), these low circuit depths can be achieved without classical optimization of parameters (whose sensitivity to noise and scaling behavior is not well understood).

Extrapolating their numerical simulation results, the team estimated that there may be a quantum speedup for this problem with a 2-qubit gate infidelity around 10-5 and roughly 2000 qubits. Our H1 system already boasts a world-class 2-qubit gate infidelity of 8.8 × 10-4, and we are well on our way towards even better fidelity with more qubits. You can see our roadmap here, and read the paper here.

In the meantime, the paper proposes that this method could be used as a quantum computing benchmark for application-oriented problems, making a valuable contribution to the Bench-QC project, of which Quantinuum is a founding member.

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April 16, 2024
Quantinuum extends its significant lead in quantum computing, achieving historic milestones for hardware fidelity and Quantum Volume

By Ilyas Khan, Founder and Chief Product Officer, Jenni Strabley, Sr Director of Offering Management

All quantum error correction schemes depend for their success on physical hardware achieving high enough fidelity. If there are too many errors in the physical qubit operations, the error correcting code has the effect of amplifying rather than diminishing overall error rates. For decades now, it has been hoped that one day a quantum computer would achieve “three 9's” – an iconic, inherent 99.9% 2-qubit physical gate fidelity – at which point many of the error-correcting codes required for universal fault tolerant quantum computing would successfully be able to squeeze errors out of the system.

That day has now arrived. Building on several previous laboratory demonstrations 1 2 3, Quantinuum has become the first company ever to achieve “three 9's” in a commercially-available quantum computer, with the first demonstration of 99.914(3)% 2-qubit gate fidelity, showing repeatable performance across all qubit pairs on our H1-1 system that is constantly available to customers. This production-environment announcement is a marked difference to one-offs recorded in carefully contrived laboratory conditions. This demonstrates what will fast become the expected standard for the entire quantum computing sector.

Quantinuum is also announcing another milestone, a seven-figure Quantum Volume (QV) of 1,048,576 – or in terms preferred by the experts, 220 – reinforcing our commitment to building, by a significant margin, the highest-performing quantum computers in the world.

These announcements follow a historic month that started when we proved our ability to scale our systems to the sizes needed to solve some of the world’s most pressing problems – and in a way that offers the best path to universal quantum computing.  

On March 5th, 2024, Quantinuum researchers disclosed details of our experiments that provide a solution to a totemic problem faced by all quantum computing architectures, known as the wiring problem. Supported by a video showing qubits being shuffled through a 2-dimensional grid ion-trap, our team presented concrete proof of the scalability of the quantum charge-coupled device (QCCD) architecture used in our H-Series quantum computers

Stop-motion ion transport video showing a chosen sorting operation implemented on an 8-site 2D grid trap with the swap-or-stay primitive. The sort is implemented by discrete choices of swaps or stays between neighboring sites. The numbers shown (indicated by dashed circles) at the beginning and end of the video show the initial and final location of the ions after the sort, e.g. the ion that starts at the top left site ends at the bottom right site. The stop-motion video was collected by segmenting the primitive operation and pausing mid-operation such that Yb fluorescence could be detected with a CMOS camera exposure.

On April 3rd, 2024 in partnership with Microsoft, our teams announced a breakthrough in quantum error correction that delivered as its crowning achievement the most reliable logical qubits on record.

We revealed detailed demonstrations in an arXiv pre-print paper of the reliability achieved via 4 logical qubits encoded into just 30 physical qubits on our System Model H2 quantum computer. Our joint teams were able to demonstrate logical circuit error rates far below physical circuit error rates, a capability that our full-stack quantum computer is currently the only one in the world with the fidelity required to achieve. 

Explaining the importance of 2-qubit gate fidelity

Reaching this level of physical fidelity is not optional for commercial scale computers – it is essential for error correction to work, and that in turn is a necessary foundation for any useful quantum computer. Our record two-qubit gate fidelity of 99.914(3)% marks a symbolic inflection point for the industry: at ”three 9's” fidelity, we are nearing or surpassing the break-even point (where logical qubits outperform physical qubits) for many quantum error correction protocols, and this will generate great interest among research and industrial teams exploring fault-tolerant methods for tackling real-world problems.

Without hardware fidelity this good, error-corrected calculations are noisier than un-corrected computations. This is why we call it a “threshold” – when gate errors are “above threshold”, quantum computers will remain noisy no matter what you do. Below threshold, you can use quantum error correction to push error rates way, way down, so that quantum computers eventually become as reliable as classical computers.  

Four years ago, Quantinuum claimed that it would improve the performance of its H-Series quantum computers by 10x each year for five years, when measured by the industry’s most widely recognized benchmark, QV (an industry standard not to be confused with less comprehensive metrics such as Algorithmic Qubits). 

Today’s achievement of a 220 QV – which as with all our demonstrations was achieved on our commercially-available machine – shows that our team is living up to this audacious commitment. We are completely confident we can continue to overcome the technical problems that stand in the way of even better fidelity and QV performance. Our QV data is available on GitHub, as are our hardware specifications

The combination of high QV and gate fidelities puts the Quantinuum system in a class by-itself – it is far and away the best of any commercially-available quantum computer.

A diagram of a circuitDescription automatically generated
Figure 1: Quantum Volume (QV) heavy output probability (HOP) as a function of time-ordered circuit index. The solid blue line shows the cumulative average while the green region shows the two-sigma confidence interval based on bootstrap resampling. A QV test is passed when the lower two-sigma confidence interval crosses 2/3.
A graph with numbers and a lineDescription automatically generated
Figure 2. Quantum volume vs time for our commercial systems. Quantinuum’s new world record quantum volume of 1,048,576 maintains our self-imposed goal of a 10-fold increase each year. In fact, in 2023 we achieved an overall increase in quantum volume of >100x.
A graph with a line and numbersDescription automatically generated with medium confidence
Figure 3. Two-qubit randomized benchmarking data from H1-1 across the five gate zones (dashed lines) and average over all five gate zones (solid blue line). The survival probability decays as a function of sequence length, which can be related to the average fidelity of the two-qubit gates with standard randomized benchmarking theory. With this data, we can claim that not only are all zones consistent with 99.9, but all zones are >99.9 outside of error bars.
QCCD: the path to fault tolerance

Additionally, and notably, these benchmarks were achieved “inherently”, without error mitigation, thanks to the H Series’ all-to-all connectivity and QCCD architecture. Full connectivity results in less errors when running large, complicated circuits. While other modalities depend on error mitigation techniques, such techniques are not scalable and present only a modest near-term value. 

Lower physical error and high connectivity means our quantum computers have a provably lower overhead for error-corrected computation.

Looking more deeply, experts look for high fidelities that are valid in all operating zones and between any pair of qubits. In contrast to our competitors, this is precisely what our H Series delivers. We do not suffer from a broad distribution of gate fidelities between different pairs of qubits, meaning that some pairs of qubits have significantly lower fidelities. Quantinuum is the only quantum computing company with all qubit pairs boasting above 99.9% fidelity.

Alongside these benefits and demonstrations of scalability, fidelity, connectivity, and reliability, it is worth noting how these features impact what arguably matters the most to users – time to solution. In the QCCD architecture, speed of operations is decoupled from speed to reach a computational solution thanks to a combination of:

  • a better signal to noise ratio than other modalities
  • drastically reducing or eliminating the number of swap gates required (because we can move our ions through space), and
  • reducing the number of trials required for an accurate result.

The net effect is that for increasingly complex circuits it takes a high-fidelity QCCD-type quantum computer less time to achieve accurate results than other 2D connected or lower-fidelity architectures.

“Getting to three 9’s in the QCCD architecture means that ~1000 entangling operations can be done before an error occurs. Our quantum computers are right at the edge of being able to do computations at the physical level that are beyond the reach of classical computers, which would occur somewhere between 3 nines and 4 nines. Some tasks become hard for classical computers before this regime (e.g. Google’s random circuit sampling problem) but this new regime allows for much less contrived problems to be solved. At that point, these machines become real tools for new discoveries – albeit they will still be limited in what they can probe, likely to be physics simulations or closely related problems,” said Dave Hayes, a Senior R&D manager at Quantinuum.

“Additionally, these fidelities put us, some would say comfortably, within the regime needed to build fault-tolerant machines. These fidelities allow us to start adding more qubits without needing to improve performance further, and to take advantage of quantum error correction to improve the computational power necessary for tackling truly large problems. This scaling problem gets easier with even better fidelities (which is why we’re not satisfied with 3 nines) but it is possible in principle.”

Quantinuum’s new records in fidelity and quantum volume on our commercial H1 device are expected to be achieved on the H2, once upgrades are implemented, underscoring the value that we offer to users for whom stability, reliability and robust performance are pre-requisites. The quantum computing landscape is complex and changing, but we remain at the head of the pack in all key metrics. The relationship with our world-class applications teams means that co-designed devices for solving some of the world’s most intractable problems are a big step closer to reality.

Quantinuum is the world’s leading quantum computing company, and our world-class scientists and engineers are continually driving our technology forward while expanding the possibilities for our users. Their work on applications includes cybersecurity, quantum chemistry, quantum Monte Carlo integration, quantum topological data analysis, condensed matter physics, high energy physics, quantum machine learning, and natural language processing – and we are privileged to support them to bring new solutions to bear on some of the greatest challenges we face.