Quantinuum Confronts Fault-Tolerant Hurdles on Road to 2029

The world’s largest integrated quantum firm identifies engineering, error correction, and ecosystem building as the decisive steps ahead

Waseem Shiraz, senior vice president at Quantinuum (Photo: Jeff Pao)

Fault-tolerant quantum computing has long been described as the holy grail of the field, and Quantinuum is staking its future on achieving it by 2029. Success will depend not just on hardware advances, but on solving interconnected challenges at an engineering scale, error correction, and ecosystem building. These factors will decide whether quantum machines become practical engines of discovery or remain confined to labs.

Error correction is viewed as the most challenging obstacle. Stabilizing qubits under real-world conditions is essential for reliability, while integration with AI and high-performance computing is needed to ensure outputs with commercial value. Without progress on both fronts, fault tolerance will remain out of reach.

“We are now entering into this age of acceleration where we have gone from understanding the science into an engineering phase,” said Waseem Shiraz, senior vice president at Quantinuum. “Our roadmap is the most de-risked in the industry.”

Shiraz made the remarks during a fireside chat with Eric Van der Kleij, cofounder and partner at Edenbase, at the launch of QBase, a new London quantum hub, on September 24.

Their exchange highlighted how London is positioning itself as a hub of quantum activity, bringing together startups, researchers, and established firms to translate experimental advances into practical applications.

Roadmap milestones

In April 2024, Quantinuum and Microsoft announced a breakthrough in logical quantum computing, demonstrating qubits with error rates hundreds of times lower than physical qubits and achieving resilient level-two performance—a milestone that underscored reliability, scalability, and the company’s claim to industry leadership.

Shiraz said Quantinuum’s credibility would rest on scaling such breakthroughs into larger systems.

The immediate focus is Helios, a system launching later this year with 50 logical qubits. He said it would act as a proving ground for the next phase, beginning to explore the intersection of classical and quantum computation and providing a platform for hybrid applications.

The next milestone is set for 2027, when Quantinuum aims to cross the 100 logical qubit threshold. Shiraz noted this would enable meaningful chemistry simulations and hybrid workflows beyond the reach of classical computing.

Achieving that goal, he added, will require more than new hardware, with tight integration of middleware and domain-specific applications. The company believes its full-stack model—combining hardware, operating software, and domain-specific algorithms—offers the best way to achieve that integration.

Finally, the target for 2029 is complete fault tolerance. Shiraz described this as the culmination of years of engineering, partnerships, and sustained investment, positioning quantum as a technology capable of tackling society’s most complex problems.

From discovery to engineering

“The past decade was the age of discovery, where we validated the fundamental science of quantum,” Shiraz said. “Now we are engineering and scaling our systems so they are capable of handling larger and larger problems.”

Error correction, certified randomness, and hybridization with AI are early proof points; however, achieving complete fault tolerance by 2029 will require continual refinement of these building blocks.

The complexity also extends to industry adoption. Even as systems grow more powerful, practical impact depends on building partnerships with corporations that bring domain expertise and data. Quantinuum has made this a priority, collaborating with energy, pharmaceutical, and materials companies.

Shiraz emphasized that breakthroughs in food security, sustainable energy, and drug discovery can only be achieved when quantum is combined with industry knowledge.

He pointed to three examples where convergence of quantum, AI, and high-performance computing could make the most significant difference:

• Fertilizer production: which consumes about 5% of global energy output, could be reinvented with quantum chemistry to replicate photosynthesis more efficiently.

• Carbon capture and clean energy: current processes remain inefficient, but quantum approaches may enable breakthroughs in battery design and catalyst development.

• Life sciences: quantum-enhanced simulation of DNA information could accelerate drug discovery, lowering costs, shortening timelines, and targeting disease at its root cause rather than its symptoms.

Global momentum, local constraints

Two major forces created Quantinuum as it exists today.

In November 2021, Cambridge Quantum merged with Honeywell Quantum Solutions. Cambridge Quantum contributed software expertise, while Honeywell brought hardware leadership and industrial backing. The merger created the world’s largest integrated quantum computing company, providing Quantinuum with a full-stack model that spans hardware, middleware, and applications.

Despite its size and global footprint, Quantinuum faces competitive and geopolitical pressures. Governments worldwide are investing heavily in quantum, from the US and Germany to China and Japan.

Shiraz observed that the UK benefits from a strong tertiary education sector in physics, mathematics, chemistry, and computing, but added that scaling commercial applications will be the country’s next test.

Japan has already deployed Quantinuum’s systems alongside the Fugaku supercomputer, one of the world’s most powerful computing machines. Singapore has integrated Quantinuum into its national strategy for computational biology.

In Qatar, the firm is collaborating on quantum-enabled energy and chemistry solutions. Partnerships with Nvidia and SoftBank further underscore the company’s role as a global player, demonstrating how government programs and private enterprises are mobilizing around the technology.

The company also grapples with balancing energy efficiency and scale. Quantum systems already demonstrate enormous advantages over classical computing, with experiments consuming tens of thousands of times less energy than traditional supercomputers. Yet, as AI workloads continue to grow exponentially, integrating quantum computing into sustainable infrastructures will remain an operational challenge.

“It’s a bit like a light bulb compared to a building’s energy requirements,” Shiraz said.

The capital challenge

Financing this trajectory demands patience and discipline. Quantinuum has raised $2.3 billion, primarily from Honeywell and strategic customers, deliberately avoiding short-term venture capital. Shiraz said the industry requires “smart, long-term, patient capital.”

He explained that many of its investors had begun as customers before becoming shareholders, underscoring the credibility of its long-term business model.

When asked about the broader economic implications, Shiraz said quantum could drive GDP growth across multiple sectors.

“Even if you take fertilizer production, steel, and batteries, and then layer that with biology and genomics, the question is what is going to be the GDP impact. Is it 1%, 5% or even 10%? Whatever it might be, I think it’s going to be very significant.”

A modest 7% increase in GDP, he added, would be enough to double economic output within a decade.

Partnering for breakthroughs

For corporate leaders, Shiraz’s advice was direct: quantum must be placed at the center of business strategies for the coming cycle. Governments and global corporations are already mobilizing, and those that wait risk losing competitiveness. For researchers, especially in medicine and life sciences, partnerships with Quantinuum offer an opportunity to co-develop solutions.

He noted that the problems the company is tackling require domain expertise, so partnerships with industry leaders are essential. Quantinuum brings its full stack and algorithmic expertise, while partners contribute their knowledge and data.

He also acknowledged the importance of inclusivity in the quantum revolution. With billions of people worldwide still lacking internet access, there is a risk of deepening the digital divide if quantum remains restricted to advanced economies.

“We want this technology in the hands of as many people as possible,” Shiraz emphasized.

Quantinuum aims not only to build more powerful machines but to overcome the engineering, economic, and collaborative hurdles that will decide whether fault-tolerant quantum computing becomes the defining technology of the next industrial era.

Looking to 2029, Shiraz said the goal is to turn those foundations into real-world impact across industries, with London and other global hubs shaping the next phase of computing. He stressed that the race to fault tolerance is not just Quantinuum’s challenge but an international contest that will set the pace of the quantum revolution, with consequences reaching far beyond the laboratory.