Fig. 3
Energy cuts on the phonon dispersions. a–d Correspond to the energy cuts on the dispersions plotted in Fig. 2a–d at different q values. The cuts are offset so that each cut can be visualized clearly. In c due to the large intensity difference of phonons at small and large qs, we plot the square root of the intensities as a function of energy so that the cut profiles at large qs can be visible. Solid lines are fits with Lorentzian functions convoluted the instrumental resolutions, as indicated by the horizontal bars. From the fits, we obtain the phonon dispersions, which are plotted as solid lines in Fig. 2. Errors represent one standard deviation throughout the paper
