Extended Data Fig. 4.

Fit gain. We compare the estimated F_z and F_y from a fit using Eq. (2); first, with the classical parameters g, ω_L, T₂ and φ₀, fixed (labeled $F_{y,z}^{(\text{fix})}$) for measurements 1 and 2; and second, free to vary as independent parameters (labeled $F_{y,z}^{\text{(ind)}}$). In blue (green) F_z (F_y) of the first measurement, in red (orange) F_z (F_y) of the second measurement. A linear fit γx + δ to points of plots a-d gives γ_a = 0.9981(8), γ_b = 1.0026(8), γ_c = 0.9923(4), γ_d = 1.0007(5) and δ_a = 0.003(1), δ_b = 0.0001(9), δ_c = 0.0004(3), δ_d = −0.0023(3), where the subscripts refer to the values shown in plots a-d. A grey line y = x is plotted on both the figures.