Silicon-based spin qubits offer a potential pathway toward realizing a
scalable quantum computer owing to their compatibility with semiconductor
manufacturing technologies. Recent experiments in this system have demonstrated
crucial technologies, including high-fidelity quantum gates and multiqubit
operation. However, the realization of a fault-tolerant quantum computer
requires a high-fidelity spin measurement faster than decoherence. To address
this challenge, we characterize and optimize the initialization and measurement
procedures using the parity-mode Pauli spin blockade technique. Here, we
demonstrate a rapid (with a duration of a few us) and accurate (with >99%
fidelity) parity spin measurement in a silicon double quantum dot. These
results represent a significant step forward toward implementing
measurement-based quantum error correction in silicon