Skip to content
ContentLora

    Tip: press / anywhere to search.

    technology

    Topological qubits

    Also known as Majorana qubits, Majorana 1, topological quantum computing

    Topological qubits are a proposed qubit design that would rely on exotic Majorana states of matter; Microsoft announced Majorana 1, which it calls the first topological-core chip, in February 2025.[1] The claim is disputed: Nature's reviewers said the paper was not evidence of Majorana modes, and a 2026 critique in Nature alleged coding errors and selective reporting.[2][3]

    Editor reviewedUpdated Quantum computingComputingPhysics
    Key facts

    The idea

    A topological qubit would store information in a special state of matter built around Majorana modes, which Microsoft says can be engineered in an indium arsenide and aluminium material it calls a “topoconductor”.[1] Microsoft argues the design offers a path to a million qubits on a single chip that fits in the palm of a hand.[4] It also says its measurement approach lets qubits be controlled digitally rather than by finely tuned analog signals, and that it expects the approach to produce industrially useful machines “in years, not decades”.[5] By contrast, today’s superconducting and trapped-ion machines rely on error correction applied on top of noisy physical qubits.[6][7]

    Majorana 1

    On 19 February 2025 Microsoft announced Majorana 1, an eight-qubit chip it described as the world’s first powered by a topological core, alongside a paper in Nature.[1] Microsoft says it designed and fabricated much of the indium arsenide and aluminium materials stack atom by atom.[8] Two weeks earlier, on 6 February 2025, DARPA had selected Microsoft, together with photonics company PsiQuantum, for the final phase of its US2QC programme, which assesses whether an approach can reach a utility-scale, error-corrected machine.[9] DARPA said more than 50 experts from its test and evaluation team had examined both companies’ plans, and described Microsoft’s design as a compact superconducting topological qubit architecture.[10]

    The dispute

    The announcement drew immediate scepticism. The Nature paper itself did not claim a topological qubit, and the journal’s peer-review file stated that the results “do not represent evidence for the presence of Majorana zero modes”.[2] On 24 June 2026 Nature published a critique by a University of St Andrews physicist arguing that Microsoft’s claims rested on coding errors and a flawed tune-up protocol, and that data contradicting them were not presented.[3] The critique says that simply shifting measurement windows could flip Microsoft’s “topological gap protocol” between classifying the same device region as suitable or unsuitable, and that raw conductance data show a disordered system with signatures of ordinary quantum dots that could explain the measurements.[11] Critics also point out that the existence of Majorana modes in such devices remains unproven and that an earlier, 2021 Nature paper in this research line was retracted.[12]

    ContentLora could not verify a primary-source response from Microsoft to the 2026 critique, so this page does not characterise one.

    Status in 2026

    Despite the dispute, Microsoft remains in DARPA’s Quantum Benchmarking Initiative, where it entered Stage C, the hardware verification stage, from the US2QC pilot.[13] DARPA describes Stage C as the point where it moves “from plans to proof”, scrutinising whether hardware performs as models and roadmaps predict.[13] DARPA stresses that QBI is not a competition and is not meant to pick winners, but to assess whether each approach has a credible path to utility scale.[14] Whether Microsoft can show unambiguous topological protection in that process is one of the field’s clearest open questions.[2] For the broader argument over what counts as a quantum milestone, see the quantum advantage debate.

    Questions readers ask

    Has Microsoft built a topological qubit?

    Microsoft says Majorana 1 is the first chip with a topological core, but the peer-reviewed paper did not claim a topological qubit and its reviewers said the results were not evidence of Majorana zero modes.[1][2]

    Why does Microsoft pursue topological qubits?

    Microsoft says the architecture offers a path to a million qubits on a single palm-sized chip.[4]

    What did the 2026 Nature critique say?

    A University of St Andrews physicist argued that Microsoft's claims rested on coding errors and a flawed tune-up protocol, and that only favourable results were presented.[3]

    Sources

    Each numbered claim is a statement we checked against the sources listed with it. Status shows how well established it is.

    1. [1]

      On 19 February 2025 Microsoft announced Majorana 1, an eight-qubit chip it described as the first powered by a topological core, built from an indium arsenide and aluminium "topoconductor", alongside a peer-reviewed paper in Nature. confirmedas of 2025-02-19

    2. [2]

      The Nature peer-review file for Microsoft's 2025 paper stated that its results do not represent evidence for Majorana zero modes, and the paper itself did not claim a topological qubit. confirmedas of 2025-02-25

    3. [3]

      On 24 June 2026 Nature published a critique by a University of St Andrews physicist arguing that Microsoft's 2025 claims rested on coding errors and a flawed tune-up protocol, and that Microsoft presented only favourable outcomes. confirmedas of 2026-06-24

    4. [4]

      Microsoft says its topological architecture offers a path to a million qubits on a single palm-sized chip. confirmedas of 2025-02-19

    5. [5]

      Microsoft says its topological core builds error resistance into the hardware and lets qubits be controlled digitally, and that it expects the approach to yield industrially useful machines in years, not decades. confirmedas of 2025-02-19

    6. [6]

      Google reported that as it scaled Willow's encoded qubit grids from 3x3 to 5x5 to 7x7, the logical error rate halved at each step, which it called the first below-threshold error correction. confirmedas of 2024-12-09

    7. [7]

      In March 2026 Quantinuum researchers reported computations with up to 94 error-detected and 48 error-corrected logical qubits on Helios, using iceberg and concatenated codes, with logical gate errors around one in ten thousand - better than the physical gates. confirmedas of 2026-03-10

    8. [8]

      Microsoft says it designed and fabricated much of the indium arsenide and aluminium materials stack for Majorana 1 atom by atom. confirmedas of 2025-02-19

    9. [9]

      In February 2025 DARPA selected Microsoft (topological qubits) and PsiQuantum (photonic qubits) for the final phase of its US2QC programme, evaluating whether each could build a utility-scale, error-corrected quantum computer. confirmedas of 2025-02-06

    10. [10]

      DARPA said more than 50 experts from its test and evaluation team examined Microsoft's and PsiQuantum's approaches, and described Microsoft's design as a compact superconducting topological qubit architecture. confirmedas of 2025-02-06

    11. [11]

      The 2026 critique says that shifting measurement windows could flip Microsoft's topological gap protocol between classifying the same device region as suitable or unsuitable, and that raw conductance data show a disordered system with signatures of non-topological quantum dots. confirmedas of 2026-06-24

    12. [12]

      Critics note that the existence of Majorana modes in these devices remains unproven, and that a 2021 Nature paper in this line of research was retracted. confirmedas of 2026-06-24

    13. [13]

      On 7 October 2026 DARPA advanced Atom Computing, Diraq, IBM and IonQ to QBI Stage C, joining Microsoft and PsiQuantum, which entered from the US2QC pilot. confirmedas of 2026-10-07

    14. [14]

      DARPA says QBI is not a competition between companies and is not intended to pick winners and losers, but to assess whether different approaches offer credible paths to utility-scale operation. confirmedas of 2026-10-07

    Revision history (2)
    1. Page created.
    2. Added Microsoft's claims about digital control and timelines, the specific flaws alleged in the 2026 critique, DARPA's review process and Stage C context.

    Created Oct 10, 2026. Last reviewed by an editor on Oct 10, 2026. Next scheduled review: Jan 10, 2027.

    Cite this page

    "Topological qubits." ContentLora, updated Oct 10, 2026. https://contentlora.com/wiki/topological-qubits

    Spotted an error? Suggest a correction or emailcorrections@contentlora.com.

    Keep exploring

    Connections
    DARPA Quantum Bench… Evaluated in
    ☰ Contents