Fig. 4
Effective exchange with detuning. Exchange energy splitting \(\left| {E_{S_{\mathrm{H}}}(\varepsilon ) - E_{T_0}(\varepsilon )} \right|\) as a function of detuning ε, as extracted from the spin-funnel (Similar to Fig. 2d, see Supplementary Note 5 and Supplementary Fig. 4), Landau–Zener–Stueckelberg interferometry (Fig. 2g), coherent exchange oscillations (Fig. 3d) and ESR funnel data (Fig. 3f). Each include 95% confidence intervals based on data fits uncertainties or measurement resolution. The solid/dashed lines represent fits to the data based on the model Hamiltonian in Eq. (1), for which we find tc(ε = 0) = 1.86 ± 0.03 GHz
