Fig. 3: Phonon mode-selective Fourier amplitude analysis of the TRARPES data.

a ARPES intensity map at Δt = 120 fs in comparison to Fourier maps at different phonon frequencies. Fourier maps were generated from ARPES intensity maps that were binned over regions of 23 meV × 0.01 Å⁻¹ in order to improve the signal statistics. Arrows indicate energy-momentum regions that are discussed in more detail in the main text. The cross marks the position of ROI E. Fourier maps of the 4.00 THz mode and the 6.35 THz mode are shown in Supplementary Fig. 5. b Transient peak energy E_band and peak width ΔE (FWHM) of the ARPES signal marked by the black arrow in a. The data result from Gaussian fits of the transient EDCs at \(\overline{\Gamma }\). PE intensity was integrated over a momentum window of 0.05 Å⁻¹. c Fourier amplitude spectra of the transients shown in b. The peaks below 0.23 THz cannot be assigned to any phonon modes in Td-WTe₂. Their origin is discussed in Supplementary Note 2.