Fig. 1
From: Spatial noise filtering through error correction for quantum sensing
The achievable sensitivity with different schemes for a 3-qubit sensor under noise correlations cij = −γ/2, for all i ≠ j. Note that sensitivity is a measure of the smallest resolvable signal per unit time, so a smaller sensitivity indicates better performance. The active recovery and GHZ schemes use codewords (10) and (12) respectively, whereas the parallel scheme operates the qubits individually, without entanglement. The active and GHZ schemes give identical performance (in the regime of Δt → 0 for the former), and both outperform parallel sensing by a factor that grows with the correlation strength γ. The details of this calculation are provided in the Supplementary Information.
