What it is
Microsoft demonstrated a single-shot interferometric measurement of fermion parity in an indium-arsenide/aluminium nanowire device, the readout a future topological qubit requires. Tunnel-coupling the proximitized nanowire to quantum dots shifted their quantum capacitance by up to 1 femtofarad, giving a parity measurement with an assignment error probability of 1% and a state dwell time longer than 1 millisecond at about 2 tesla.
Why it matters
Topological qubits promise intrinsic error protection but require measuring Majorana parity. A fast, low-error, single-shot parity readout is a prerequisite the field has chased for years.
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Filed undertopological qubits, majorana, parity measurement, semiconductor nanowire, quantum computing