Repetitive single electron spin readout in silicon

Understand

Single electron spins confined in silicon quantum dots hold great promise as a quantum computing architecture with demonstrations of long coherence times, high-fidelity quantum logic gates, basic quantum algorithms and device scalability.

• While single-shot spin detection is now a laboratory routine, the need for quantum error correction in a large-scale quantum computing device demands a quantum non-demolition (QND) implementation.
• Unlike conventional counterparts, the QND spin readout imposes minimal disturbance to the probed spin polarization and can therefore be repeated to extinguish measurement errors.
• However, it has remained elusive for an electron spin in silicon as it involves exquisite exposure of the system to the external circuitry for readout while maintaining the coherence and integrity of the qubit.