Topological qubits promise fault-tolerant quantum computing but remain scientifically contested. Discuss the promise and the controversy, and the implications for India's National Quantum Mission.

Topological qubits store quantum information in exotic states called Majorana zero modes. Their design is meant to protect them from noise, so they would not need heavy error correction added on top [1]. Microsoft's Majorana chips make this the field's most promising approach, and also its most disputed one.

The Promise

• Built-in fault tolerance: they could sharply cut the error-correction burden that limits superconducting and ion-trap machines [1].
• Scalability: Majorana 1 had 8 qubits on a new "topoconductor" material (indium arsenide–aluminium). Microsoft claims a path to one million [1].
• Real progress: the Nature paper showed single-shot parity measurement, which it called a "necessary ingredient" for topological computing [1].

The Controversy

• Paper vs. press release: the peer-reviewed paper was "considerably more circumspect" than the claim of the "world's first topological qubits" [1].
• Missing proof: a parity measurement is necessary but not sufficient. Nobody has yet shown braiding of Majorana modes, which is how they would carry out a calculation [1].
• Track record: a 2018 Nature paper on "Quantized Majorana conductance" was retracted in 2021. Frolov and Mourik found that the raw data did not match the published figures [2]. Frolov now doubts the foundation of Majorana 2 [1].
• Ethics: the commercial value of being first rewards over-claiming, which erodes trust in science.

Implications for the NQM

• Spreading the risk pays off: the NQM (₹6,003.65 crore, 2023-24 to 2030-31) targets 50–1,000 physical qubits on platforms such as superconducting and photonic [3][4]. It is not tied to the unproven topological approach.
• Capability gap: if topological qubits succeed, India has no group building that hardware. Small materials-physics grants through the NQM's thematic hubs would keep the option open.
• Slow spending: by February 2026, about ₹2,330.68 crore had been sanctioned but only about ₹699.50 crore released [5]. Money that sits unused cannot shift to the approach that starts to win.
• Verification norms: DST could tie milestone funding to raw-data sharing and reproduction by another lab, so the 1,000-qubit target stays a verified result rather than a headline.

Topological qubits are a step forward that has not yet been shown to work. Microsoft has shown a building block, not the qubit itself. India's multi-platform strategy is sound. Faster spending and openness to new approaches would strengthen it, and so would independent checking of results. This would build trustworthy quantum capability for Atmanirbhar Bharat and SDG-9.