Physics / mechanism
Topological qubits encode quantum information in non-abelian anyons—specifically Majorana zero modes (MZMs)—that emerge at the ends of proximitized semiconductor nanowires (InAs or InSb) coupled to superconductors (Al). Information lives non-locally across spatially separated MZM pairs, making it intrinsically protected from local perturbations. Error rates scale exponentially with MZM separation rather than requiring active correction overhead. Microsoft’s Majorana 1 chip (Feb 2025) demonstrated a topological gap of ~30 µeV and MZM lifetime >1 µs on a 8-qubit device. Target metric is topological gap protocol (TGP) fidelity; Microsoft claims threshold crossings but peer-reviewed fault-tolerance benchmarks remain outstanding. Physical qubit count is tiny vs. superconducting competitors—roadmap targets logical qubits within ~5 years.
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