Fig. 3. Enhanced magnon–magnon coupling strength.

a Enhancement of the anticrossing gap by by rotating the external magnetic field by an oblique angle Θ along the out-of-plane direction at $45^{\circ }$ to the in-plane principal a-axis as indicated. b $\mathrm{\Theta }$ dependence of the coupling strength $g_c$ and the dissipation rates for the upper and lower magnonic branches, ${\kappa }_U$ and ${\kappa }_L$ derived from the frequency-field dependence of resonance spectra presented in (c). The dotted red line is the fitted curve for the coupling strength following a quadratic behavior. The insets in (c) highlight the resonance spectra under an adjusted color scale, showing the increased DMI-induced nonzero gap, $f_g$ of the ‘dark’ mode as $\mathrm{\Theta }$ increases.