Physicists challenge Microsoft’s quantum computing breakthrough

Microsoft introduced the Majorana 1 in February 2025, positioning its topological qubit design as the essential building block for a scalable quantum computer. The company recently doubled down on this trajectory by unveiling the Majorana 2 chip at the Build conference earlier this month. However, Legg’s re-analysis casts significant doubt on whether these devices actually achieved the specific particle behavior required for the technology to function as described.

The core of Microsoft’s approach relies on a specialized wire made of indium arsenide, thinner than a human hair, fused to a superconductor. Theoretical models suggest that electrons within this structure should organize into collective patterns known as Majorana particles. Microsoft intends to use these particles to encode information, a strategy that sets them apart from the superconducting circuits favored by competitors like Google and IBM. While those companies have produced more advanced hardware, the industry remains in a state where no machine has yet performed a demonstrably useful calculation. The validity of Microsoft’s path now hinges on whether their signature particle, the namesake of their hardware, is truly present.