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The critique was authored by Dr Henry Legg of the University of St Andrews School of Physics and Astronomy. It targets the February 2025 Nature paper in which Microsoft unveiled its Majorana 1 chip, billed as the world's first quantum processor powered by topological qubits. Published in Nature's "Matters Arising" section, the venue for formal criticism of the journal's own papers, Legg's analysis lands at the heart of one of the most ambitious bets in the technology industry.
The critique further alleges that coding errors in Microsoft's data processing caused the company to omit critical regions of the device's phase space, regions that peer reviewers had explicitly asked to be checked. Legg also contends that the raw conductance data reveals a "highly disordered system" rather than the pristine topological gap that quantum computing demands.
"Last year Microsoft claimed they had built the equivalent of a precision Swiss watch," Legg told the BBC. "However, when I opened the case to examine the mechanism, I found what looked like a chaotic jumble of mismatched parts."
Still, physicists remain concerned that Microsoft has not released enough public data to allow independent verification. As Legg concluded: "I am simply reflecting what most in the field felt from the initial announcement. I felt that I needed to put these concerns into a formal scientific critique."
Nature Critique Questions Microsoft's Majorana Quantum Chip Claims
June 25, 2026
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A peer-reviewed critique in Nature by University of St Andrews physicist Dr Henry Legg alleges that Microsoft's quantum validation software contained coding errors and can produce contradictory results. Microsoft stands by its work and has pressed ahead with Majorana 2, a chip it says is 1,000 times more reliable, while aiming for a commercial quantum computer by 2029.
A Formal Challenge in Nature
Microsoft's headline-grabbing quantum computing breakthrough is facing fresh scrutiny. A peer-reviewed critique published in the journal Nature has raised pointed questions about the company's claimed progress, alleging that the validation software underpinning its results contained coding errors and could produce contradictory conclusions depending on arbitrary measurement choices.The critique was authored by Dr Henry Legg of the University of St Andrews School of Physics and Astronomy. It targets the February 2025 Nature paper in which Microsoft unveiled its Majorana 1 chip, billed as the world's first quantum processor powered by topological qubits. Published in Nature's "Matters Arising" section, the venue for formal criticism of the journal's own papers, Legg's analysis lands at the heart of one of the most ambitious bets in the technology industry.
Flawed Foundations
At the centre of the dispute is the Topological Gap Protocol, an automated software test Microsoft designed to remove human bias from validating its devices. Legg argues the protocol is itself unreliable. According to the University of St Andrews, simply shifting the measurement windows can cause Microsoft's software to classify the same region of a device as either suitable or unsuitable for quantum computing.The critique further alleges that coding errors in Microsoft's data processing caused the company to omit critical regions of the device's phase space, regions that peer reviewers had explicitly asked to be checked. Legg also contends that the raw conductance data reveals a "highly disordered system" rather than the pristine topological gap that quantum computing demands.
"Last year Microsoft claimed they had built the equivalent of a precision Swiss watch," Legg told the BBC. "However, when I opened the case to examine the mechanism, I found what looked like a chaotic jumble of mismatched parts."
A Pattern of Scrutiny
The critique arrives amid long-running scepticism about Microsoft's topological quantum programme. In 2021, researchers funded by the company retracted an earlier Nature paper claiming evidence of Majorana particles, apologising for "insufficient scientific rigour." Nature editors later added a note to Microsoft's 2025 publication stating that the findings "do not provide evidence for" Majorana zero modes as originally reported.Microsoft Presses Forward
Microsoft has defended its work. In a response also published by Nature, Microsoft Technical Fellow Chetan Nayak said, "We stand by our results and our roadmap." The company has pushed ahead with the technology, unveiling Majorana 2, a next-generation topological chip developed with the help of its agentic AI platform Microsoft Discovery. Microsoft reports that the new chip's qubits can hold information for more than 20 seconds, up from milliseconds on Majorana 1, a roughly 1,000-fold improvement. The company says it has halved its development timeline, moving its target for a scalable, commercially viable quantum computer from 2033 to 2029.Still, physicists remain concerned that Microsoft has not released enough public data to allow independent verification. As Legg concluded: "I am simply reflecting what most in the field felt from the initial announcement. I felt that I needed to put these concerns into a formal scientific critique."
Published June 25, 2026 at 10:46am
