Physicist disputes Microsoft topological qubit evidence

A leading physicist has challenged the scientific foundation of Microsoft's quantum computing roadmap, arguing in a formal critique that the company has not demonstrated the core technology it claims will enable a commercial quantum supercomputer by 2029. The critique, published in the journal Nature on Wednesday, June 24, 2026, targets a 2025 paper in which Microsoft researchers described evidence for a topological qubit, a theoretically more stable type of quantum bit.

The author, Dr. Henry Legg, a physicist at the University of St Andrews, contends that Microsoft's findings are undermined by flawed data analysis software, omitted data, and selective reporting. He argues that basic programming errors in Python scripts used to process experimental data led to the highlighting of only favorable results while concealing contradictory data. According to Legg, the raw data suggests the signals Microsoft attributes to a topological superconducting state-essential for its approach-are more consistent with experimental noise or other quantum effects. He concluded that Microsoft has not demonstrated the basic physics required for even a single topological qubit.