Researcher Throws Cold Water on Microsoft Quantum Claims

Weeks after Microsoft unveiled Majorana 2, a quantum chip it stated was 1,000 instances extra dependable than its predecessor and a serious step towards sensible quantum computing by 2029, a number one researcher is difficult the corporate’s claims.

In a commentary printed Wednesday in Nature, College of St Andrews physicist Henry Legg argued Microsoft has did not display the existence of a topological qubit, a theoretical kind of quantum bit that may very well be extra immune to errors than standard quantum computing approaches.

“My critique exposing flawed tune-up procedures, code errors, and omitted knowledge behind Microsoft’s ‘breakthrough’ quantum computing claims is printed as we speak in Nature,” Legg wrote on BlueSky. “Briefly: Microsoft have not demonstrated the fundamental physics wanted for even a single topological qubit.”

Legg’s commentary responds to a 2025 paper printed in Nature by Microsoft Quantum researchers describing proof for the corporate’s topological qubit. In response to Legg, the indicators Microsoft attributes to the system may as an alternative be experimental noise.

“The detection of a topographical superconducting part–the idea of proposed topological qubits–is notoriously tough as a result of trivial states can mimic the signatures anticipated from a topological superconductor,” Legg wrote.



Microsoft stated Majorana 2 can maintain quantum data secure for a median of 20 seconds, with some qubits lasting as much as a minute. The corporate stated AI helped pace improvement by figuring out promising supplies, automating checks, and enhancing manufacturing. The chip depends on the identical topological qubit know-how now being questioned by critics. Microsoft argues the strategy may produce extra dependable quantum computer systems by lowering the errors that plague as we speak’s programs.

Legg argued that beforehand unpublished transport knowledge underlying Microsoft’s outcomes failed to point out clear proof of the superconducting state required to assist the corporate’s topological qubit declare. As an alternative, he stated the measurements appeared extra according to different explanations, together with quantum dot results.

Microsoft pushed again on Legg’s conclusions.

“We stand by our outcomes and our roadmap,” Chetan Nayak, Microsoft’s Technical Fellow and Company Vice President for Quantum {Hardware}, informed Scientific American. Nayak pointed to Microsoft’s development into the ultimate part of DARPA’s Quantum Benchmarking Initiative, which he stated adopted impartial analysis of each public and proprietary outcomes. “Skepticism and rigor are hallmarks of the scientific course of, which we admire and have supported from varied teachers,” he added.

Microsoft additionally printed a proper response in Nature on Wednesday, arguing that its measurements assist the conclusion that it has produced a topological qubit. The corporate stated the secure indicators noticed in its experiments are according to a topological state and can be unlikely to look if the system had been merely exhibiting noise or behaving as a gapless state, as Legg suggests.

The controversy arrives because the cryptocurrency business races to arrange for “Q-Day,” the purpose at which a quantum laptop turns into highly effective sufficient to interrupt broadly used public-key cryptography.

Bitcoin is taken into account significantly susceptible as a result of a quantum attacker may doubtlessly derive non-public keys from uncovered public keys and steal funds. Legg’s critique doesn’t rule out that future, nevertheless it does problem the proof Microsoft cites for reaching it.