Physicist Challenges Microsoft's Quantum Breakthroughs
A UK-based physicist has cast further doubt on Microsoft's assertions of significant advancements in quantum computing. Dr. Henry Legg, a long-standing critic of the company's quantum research, detailed his concerns in a paper published in the scientific journal Nature.
Software Accuracy and Unproven Particles
Dr. Legg's critique centers on two main points. Firstly, he argues that a software tool utilized by Microsoft to validate its research contains coding errors and lacks sufficient accuracy. Secondly, he claims that Microsoft has yet to conclusively prove its ability to create a theoretical quasi-particle known as a Majorana, which is fundamental to its quantum computing methodology.
Microsoft has consistently defended its findings despite ongoing skepticism from experts in the field. The tech giant has made substantial investments in the race to develop quantum computers, which operate on principles vastly different from conventional machines. These advanced computers are envisioned to tackle complex global challenges that are currently beyond the processing capabilities of even the most powerful supercomputers.
Despite the quantum computing industry already being valued at billions of dollars, currently available devices are limited and highly susceptible to errors from minor interferences like vibrations or slight temperature fluctuations.
"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," Legg stated. "Something was making noise, but it didn't look like the breakthrough Microsoft had claimed."
Microsoft's Response and Data Sharing Concerns
In response, Microsoft has reiterated its confidence in its results. Dr. Chetan Nayak, Technical Fellow and Corporate Vice President, Quantum Hardware at Microsoft, commented, "Scepticism and rigour are hallmarks of the scientific process, which we appreciate and have supported from various academics. We have participated in dialogue and our thorough rebuttal was accepted and published by Nature." Microsoft's rebuttal clarified that the software Dr. Legg referenced did not "interpret" the measurements leading to their conclusions.
Dr. Legg also accused Microsoft of not providing enough data for independent scientific scrutiny, a standard practice for validating or dismissing research within the broader expert community. Microsoft stated it is sharing all its data with Darpa, the US defense agency, for independent arbitration, but claims some data is too commercially sensitive for wider public release.
Previous Scrutiny and Ongoing Development
Dr. Legg's recent paper scrutinizes research initially published by Microsoft in 2025. Since then, Microsoft has introduced a second generation of its Majorana chip, which it asserts is 1,000 times more reliable than its predecessor.
This is not the first instance of Microsoft's quantum research facing questions. A paper from a Microsoft-backed laboratory, which claimed to have found evidence of the Majorana particle, was retracted in 2021. Furthermore, in 2025, editors at Nature added a note to Microsoft's paper claiming the creation of the particle itself, stating, "The results in this manuscript do not represent evidence for the presence of Majorana zero modes in the reported devices."
The pursuit of more reliable quantum computers is an industry-wide challenge. Microsoft maintains that its unique approach, rooted in a 90-year-old physics theory and involving a state of matter beyond liquid, solid, or gas, offers the optimal solution. The company has dedicated over two decades to this particular path in quantum computing.
Source: Scientist publishes fresh doubts over Microsoft's quantum claims