A peer-reviewed critique from the University of St Andrews published in the journal Nature provides evidence that Microsoft's claimed quantum computing "breakthrough" was built on flawed foundations.
The critique, a comment on Microsoft's Nature paper from February 2025, comes after Microsoft's announcement of quantum chips that they claim will allow practical quantum computing within "years not decades." In contrast, the analysis by Dr Henry Legg, from St Andrews School of Physics and Astronomy, reveals that Microsoft's claim rested on coding errors, a flawed tune-up protocol, and were seemingly contradicted by data not presented by Microsoft.
Dr Legg said: "Last year Microsoft claimed they had built the equivalent of a precision Swiss watch. However, when I opened the case to examine the mechanism, I found what looked like a chaotic jumble of mismatched parts. Something was making noise, but it didn't look like the breakthrough Microsoft had claimed. Despite the headlines, the vast majority of scientists in the field were sceptical of Microsoft's claim from the start; my critique simply backs up that scepticism in the scientific record."
Quantum computers are predicted to solve complex problems that are impossible for our current computers. It is claimed that they can discover new drugs, optimise global logistics, and crack encryption. However, quantum states are incredibly fragile, prone to collapsing at the slightest interference from the outside world. To solve this, Microsoft bet heavily on a unique approach called "topological quantum computing." They aim to harness elusive particles called Majoranas to create qubits that are supposed to be immune to outside interference.
However, the existence of Majoranas remains unproven, and Microsoft's pursuit of this technology has faced major credibility issues before. In 2021, researchers funded by the company were forced to retract a previous Nature paper that claimed to have found evidence of Majoranas. The authors of that paper apologised for "insufficient scientific rigour."
The Topological Gap Protocol (TGP) was supposedly Microsoft's answer to these past failures – an automated software test designed to eliminate human bias and prevent false positives. Yet, today's peer-reviewed critique provides evidence that this protocol is itself flawed. Dr Legg's analysis reveals severe issues with how Microsoft used the TGP to validate their devices:
- Simply shifting measurement windows can alter the protocol's outcome. This causes Microsoft's software to classify the exact same device region as either suitable for quantum computing ("gapped") or not suitable ("gapless") simply due to arbitrary measurement choices.
- Microsoft presented only the favourable outcomes of the protocol in their Nature publication. Contradictory results, where the TGP classified the purportedly successful regions as not suitable for quantum computing, were not shown.
- Coding errors in Microsoft's data-processing caused them to omit and completely miss exploring other critical regions of the device's phase space, despite the explicit requests of peer reviewers for these checks.
- The raw conductance data, which Microsoft did not present in their original paper, reveals a highly disordered system. Instead of the pristine topological gap required for quantum computing, the data appears to show signatures of disorder and non-topological "quantum dots" that could explain Microsoft's measurements.
This case highlights how rigorous scientific analysis can challenge even the largest technology corporations.
Dr 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. It is good that it has now been peer-reviewed and published.
