Microsoft’s new quantum computer chip has a fundamental problem

Microsoft unveiled its latest quantum chip, Majorana 2, which it claims advances topological qubit technology by leveraging Majorana quasiparticles. The chip replaces aluminum superconductors with lead, a controversial material choice, to allegedly extend qubit stability to 20 seconds to a minute. Microsoft’s Quantum team, led by Executive Vice President Jason Zander, framed the announcement as a pivotal step toward scalable quantum computing, targeting a 2029 milestone for practical applications. However, external physicists question the validity of the findings, citing a history of retractions and unproven claims. In 2021, Microsoft retracted a Nature paper after experts argued the data could stem from material flaws rather than topological qubits. Similar skepticism surrounds the Majorana 1 chip, announced last year, with critics noting the latest preprint’s data relies on limited device observations. The company’s blog post highlights accelerated progress, emphasizing the potential for millions of qubits on a single chip to outperform classical systems. Yet, Henry Legg, a physicist at the University of St. Andrews, dismissed the claims, stating the evidence is insufficient to confirm functional topological qubits. Microsoft’s roadmap now focuses on achieving scalable, error-resistant quantum computing within the next six years, despite lingering doubts from the scientific community. The Majorana 2 chip’s design aims to mitigate quantum errors by exploiting the topological properties of quasiparticles, a method Microsoft believes could surpass traditional quantum approaches. Critics argue the reliance on lead and untested claims undermines the credibility of the breakthrough, echoing past controversies in the field.