Figure 5: Comparison of data with the decay cascade model.

(a) Points: average number of pumped electrons n≡I_P/ef as a function of exit gate voltage for four combinations of magnetic field and pump frequency, using sine wave drive. Solid lines: n_FIT obtained by fitting the data to equation (1). Values of the fitting parameter δ₂ are (left–right) 12.2, 20.7, 9.1 and 4.6. (b) Solid line: close-up of the n_FIT(V_G2) line for the 1-GHz data in (a). Dotted line: derivative dn_FIT/dV_G2 (arbitrary units) that is minimized at gate voltage V_G2,MIN. The theoretically predicted pump error ≡1−n_FIT is defined for V_G2=V_G2,MIN. (c) Points: average number of pumped electrons as a function of exit gate voltage obtained from a quick low-resolution measurement (0.4 s/data point) for AWG drive at 945 MHz. Line: n_FIT obtained by fitting the data to equation (1). (d) Comparison between the fit from (c) (line) and the high-resolution data using AWG drive at 945 MHz from Fig. 3c (points) plotted on an offset gate voltage scale. (e) Fitting parameter δ₂ extracted from fits similar to those shown in (a). Horizontal dotted lines show the values of δ₂ corresponding to predicted pumping errors of 1, 0.1 and 0.01 p.p.m. The left panel shows δ₂ as a function of B for f=150 MHz, sine wave drive, and the right panel shows δ₂ as a function of f for B=14 T. Open circles: sine wave drive; closed circle: AWG drive.