A peer-reviewed paper published in Nature is challenging Microsoft’s claims about its Majorana 1 quantum computing chip, arguing that the company did not conclusively demonstrate a working topological qubit.
Microsoft unveiled Majorana 1 in February 2025, calling it a breakthrough featuring topological qubits that would serve as building blocks for a practical quantum computer. The company announced the next generation, Majorana 2, at Build earlier this month.
But Henry Legg, a physicist at the University of St Andrews, reanalyzed Microsoft’s data and found that what the company identified as a signature of the Majorana particle could actually be caused by quantum dots forming in the device. Quantum dots aren’t useful for building a quantum computer. Legg also accused Microsoft of cherry-picking data.
“They haven’t convincingly shown that they have Majoranas,” Legg told The Verge. “You can’t make a qubit if you don’t have the Majoranas.”
Microsoft published a rebuttal in Nature, with physicist Chetan Nayak stating the critique “does not constitute a substantial scientific challenge.” Legg’s paper was first posted to arXiv in February 2025 but took a full year to pass peer review. Meanwhile, Microsoft says it can build a scalable quantum computer by 2029.
It’s worth noting that no quantum computer from any company — including Google and IBM, which have more advanced machines — has yet performed anything practically useful.
