Error correction
Microsoft's Majorana chips: has it built a topological qubit?
Microsoft says its Majorana chips use a new kind of qubit that resists errors by design, and that a scalable machine could arrive by 2029. The underlying physics is still disputed, and no working topological qubit operations have been published.
- Announced
- Published
- Peer-reviewed
- Repeated
- Useful
- The claim
- Microsoft says Majorana 1 (2025) is the first chip with a "topological core" of eight qubits, and that Majorana 2 (2026) is a thousand times more reliable and brings a scalable quantum computer forward to 2029.
- What was shown
- A peer-reviewed measurement (Nature, February 2025) of the property such qubits would store, made on Microsoft's devices, and a preprint (June 2026) showing that property lasting about 20 seconds in one wire.
- What it doesn't show
- That the devices contain the Majorana states the whole approach depends on. Nature's editors wrote that the 2025 paper isn't evidence of them. No operations on topological qubits, or links between them, have been published.
- Why it matters
- If topological qubits work, they could need far less error correction than any other approach: a genuine shortcut. That's why the claim matters, and why it needs strong evidence.