A new critique in the scientific journal Nature is raising fresh questions about Microsoft’s claimed quantum computing breakthrough last year, which underpinned the company’s announcement this month that it will have a working quantum system by 2029.
Quantum computers could solve scientific and cybersecurity problems beyond the reach of conventional machines. They have become a priority for US President Donald Trump’s administration, which invested $2 billion in the field and this week set goals for a scientific quantum system by 2028.
Like rivals IBM, Alphabet’s Google and others, Microsoft is developing its own quantum computer. But while rivals are engineering machines based on better-understood quantum technologies, Microsoft has spent nearly two decades trying to break new scientific ground on a technology it says could help it leapfrog competitors.
In a formal reply to the critique and an interview with Reuters, Microsoft said it stands behind its research and that its quantum programme is making practical progress despite any concerns.
Microsoft’s scientific effort has drawn scepticism. Two previous Microsoft-backed papers were retracted from the Nature, while editors flagged alerts about possible research problems in two others, one in the Nature and another in the Science.
Microsoft said the previously retracted papers in the Nature were done outside its labs and it did not review the data in them before publication.
The peer-reviewed critique published in the Nature yesterday by Henry Legg, a lecturer in quantum physics at the University of St Andrews in Scotland, raises concerns about a fifth paper, published in February 2025, and an associated Press announcement.
The paper, which is not being retracted, is central to all of Microsoft’s subsequent quantum efforts.
Microsoft said publicly last year it had found the Majorana, a long-theorised subatomic particle central to its approach. However, it has not published that discovery in a peer-reviewed journal, such as the Nature. The February 2025 Nature paper made a narrower claim: that Microsoft had developed software to identify a minute gap in an otherwise highly conductive wire.