A leading quantum computing expert has criticized Microsoft’s assertions regarding the development of a “topological qubit,” claiming in a recent paper that the company has not successfully demonstrated this technology.
Henry Legg, a physicist from the University of St Andrews, suggests that the “topological qubit,” which is designed to store quantum information with potentially higher fidelity than existing alternatives, might merely be noise.
This critique was published today in Nature‘s “Matters Arising,” a section of the journal dedicated to formal critiques of its published papers. Legg’s commentary targets Microsoft’s latest Nature paper published earlier this month, adding to a series of criticisms directed at Microsoft’s Quantum division by other experts in the field.
On supporting science journalism
If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Microsoft has had to retract some of its previous peer-reviewed papers. In the latest commentary, Legg argues that their recent Nature paper might also have significant flaws. In response also published today by Nature, a member of Microsoft’s Quantum team contends that their data supports the claim of having produced a topological qubit.
Chetan Nayak, Microsoft’s Technical Fellow and Corporate Vice President of Quantum Hardware, told Scientific American, “We stand by our results and our roadmap. Ultimately, success means delivering a scalable quantum computer. We are confident in our ability to follow through on our plans and are proud of our ongoing collaboration with DARPA, which advanced Microsoft to the final phase of its Quantum Benchmarking Initiative after independently assessing our results—both public and proprietary—with a team of highly qualified experts. We value skepticism and rigor as hallmarks of the scientific process, and we have encouraged dialogue with various academics. Our detailed rebuttal was accepted and published by Nature.”
The critique, which Microsoft has been aware was in progress at Nature for some time, coincides with the company’s launch of the “Majorana 2” chip and an updated timeline aiming for “scalable, practical quantum computing” by the end of the decade. Legg states, “They simply cannot convincingly present the 2029 roadmap to the public when the underlying physics is not supported.”
“The ‘Matters Arising’ clearly indicates that the paper in Nature lacks scientific value,” says Sergey Frolov, a physicist at the University of Pittsburgh who was not involved in either paper. “It likely needs to be retracted, similar to other Nature papers linked to Microsoft.”
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

