Extended Data Fig. 5: Polarization dependent response and analysis of the vortexon mode.

a, Normalized change of diffraction intensity of 004 vortex Bragg peak as a function of time when the THz field is applied parallel to and perpendicular to the crystalline x-axis. b, Baseline-subtracted normalized change of diffraction intensity of the 004 vortex superlattice peak (red curve) as a function delay. Raw data shown in grey are from Fig. 4b. The green curve shows a sinusoidal wave (see Supplementary Note 5), with its minima (green arrows) deviating from the data (red arrows) at later times. The vertical dashed line indicates the time when the THz field turns on.