Fig. 2: tr-XRD signals.
a The incident THz pump pulse measured with electro-optic sampling at the sample position (see Methods for detail). b, THz pulse spectra, where blue and orange curves indicate data without and with the low-pass filter, respectively. c The (0 0 24) XRD intensity at 20 K as a function of pump-probe delay. The blue data show the XRD response for +ETHz, while the orange data show the response when inverting the phase of the THz electric field (−ETHz). d The FFT spectrum of the diffraction response. e Temperature dependence of the time-dependent diffraction intensity after insertion of a low-pass filter that cuts off components above 3 THz. f The FFT spectra of (e). Dashed lines in (a) and (e) highlight the phase shift of π/2 between the incident THz pulse and the (0 0 24) XRD intensity.
