Single-shot parity readout of a minimal Kitaev chain

Nature

by Nick van Loo

February 13, 2026

Protecting qubits from noise is essential for building reliable quantum computers. Topological qubits offer a route to this goal by encoding quantum information non-locally, using pairs of Majorana zero modes. These modes form a shared fermionic state whose occupation—either even or odd—defines the fermionic parity that encodes the qubit1. Notably, this parity can only be accessed by a measurement that couples two Majoranas to each other. A promising platform for realizing such qubits is the Kitaev chain1, implemented in quantum dots coupled using superconductors2. Even the minimal two-site chain hosts a pair of Majorana modes, often called ‘poor man’s Majoranas’, which are spatially separated but offer limited protection compared with longer chains3–5. Here we introduce a measurement technique that reads out their parity through quantum capacitance. Our method couples two Majoranas and resolves their parity in real time, visible as random telegraph switching with lifetimes exceeding a millisecond. Simultaneous charge sensing confirms that the two parity states are charge neutral and remain indistinguishable to a probe that does not couple the modes. These results establish the essential readout step for time-domain control of Majorana qubits, resolving a long-standing experimental challenge. A measurement strategy is described that is able to read out the parity of minimal two-site Kitaev chains in real time, by coupling two Majoranas and resolving their quantum capacitance.

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Originally published on Nature on 2/13/2026