Microsoft is once again facing scrutiny over its quantum breakthrough, as physicist Henry Legg published a peer-reviewed critique in the journal Nature pointing out errors in the company’s data. The critique examines Microsoft’s claims about Majorana 1 technology, which the company presented in February 2025 with the promise of bringing a full-fledged quantum computer closer to reality in just a few years.
Microsoft’s approach to quantum computing revolves around Majorana states, which are believed to create more stable qubits, the basic units of a quantum computer. The challenge lies in the experimental confirmation of these states, as they are notoriously difficult to detect. Previous controversies surrounding Microsoft’s work on quantum computing, including retractions of publications, have already cast doubt on the company’s claims.
Henry Legg, a professor at St. Andrews University, published a paper in Nature titled On the robustness of topological gap detection via transport, questioning Microsoft’s evidence of the topological gap required for topological qubits. Legg argues that Microsoft’s data does not convincingly demonstrate the occurrence of the desired mode in the experimental device.
Microsoft’s reliance on the Topological Gap Protocol for their experiment has also been called into question by Legg. He claims that the software used by Microsoft to set up the experiment was flawed, and some raw data was omitted from the original publication. Legg’s analysis suggests that the device exhibited severe disorder instead of a controlled Majorana state, casting doubt on the validity of Microsoft’s quantum breakthrough.