Fault-tolerant quantum metrology

Understand

We introduce the notion of fault-tolerant quantum metrology to overcome noise beyond our control -- associated with sensing the parameter, by reducing the noise in operations under our control -- associated with preparing and measuring probes and ancillae.

• To that end, we introduce noise thresholds to quantify the noise resilience of parameter estimation schemes.
• We demonstrate improved noise thresholds over the non-fault-tolerant schemes.
• We use quantum Reed-Muller codes to retrieve more information about a single phase parameter being estimated in the presence of full-rank Pauli noise.