Fig. 4: Determination of the two-photon detuning for the zero phase shift.
Black (or red) circles are the experimental data of phase shift versus two-photon detuning measured at α (optical depth) = 82, Ωc = 1.0Γ, Δc = 1.0Γ, and Ωp = 0.10Γ (or 0.20Γ). Black and red lines represent the linear best fits. We determined the two-photon detuning, δ0, for the zero phase shift, i.e., ϕ = 0, by the intersection between the best fit and the gray dashed line. As references, blue and green lines are the theoretical predictions calculated numerically54. The error bars represent the standard deviation of measured values.
