Fig. 3: Spin-dependent ionization.
From: Robust all-optical single-shot readout of nitrogen-vacancy centers in diamond
a Average fluorescence of the charge-state readout after charge initialization (without postselection), spin initialization according to Fig. 1c, and spin-dependent ionization with varying time. For b and c, 2 μs was used. b Distribution of the number of fluorescence photons that were detected during 1 ms of readout, after preparing the NV− in either spin |+1〉 or |0〉 and spin-dependently ionizing it for 2 μs. The as-measured fidelity is (88.5 ± 0.5)%. The dotted line indicates the threshold used for analysis. Sketches of the used sequences are inset. c Rabi oscillation measured accordingly to panel b. The y-axis is the fraction of experimental repetitions with detected photon number during readout above threshold. The data were measured within about 11 s. The red line is a cosine fit. d Sequence as used for panel b. The color-code is explained in Fig. 1.
