Access this dataset on Dryad

This dataset contains the data used to generate Fig. 1a, Fig. 1c, Fig. 1d, and the Fig. 1c inset Poincare-sphere polarization-state plot for the Comment on "Photoinduced dynamics and momentum distribution of chiral charge density waves in 1T-TiSe2" (https://doi.org/10.1103/p5d8-548h). The files include a static electron diffraction image, pump-probe delay-dependent normalized intensity changes of a selected superlattice peak, and normalized Stokes-vector coordinates describing the pump polarization states. The measurements compare responses for right-handed polarization (RHP) and left-handed polarization (LHP), including excitation with an 800 nm pump and a 10.6 um mid-infrared (MIR) pump.

Description of the data and file structure

The dataset is provided as a folder named Data.zip and contains four files:

• Fig1a.tiff
• Fig1cd_data.xlsx
• Fig1cd_insets_data.xlsx
• ReadMe.txt

Fig1a.tiff is the static electron diffraction pattern used for Fig. 1a. It is an 801 x 801 pixel, 16-bit TIFF image. Pixel values are detector counts/intensities after cropping and rotating the diffraction pattern for display. The image was generated from averaged ultrafast electron diffraction (UED) patterns.

Fig1cd_data.xlsx contains the plotted pump-probe time traces for Fig. 1c and Fig. 1d. The workbook has two sheets:

• Fig1c: data for the 800 nm pump measurement.
• Fig1d: data for the 10.6 um MIR pump measurement.

Both sheets have the same column structure:

• Delay_ps: pump-probe delay time in picoseconds.
• RHP_IntensityChange (norm.): normalized intensity change of the selected superlattice peak for right-handed pump polarization.
• RHP_Error: estimated uncertainty for the RHP trace.
• LHP_IntensityChange (norm.): normalized intensity change of the selected superlattice peak for left-handed pump polarization.
• LHP_Error: estimated uncertainty for the LHP trace.

The intensity-change columns are normalized quantities, calculated relative to the average intensity before time zero. Negative values indicate a decrease in the selected peak intensity relative to the pre-time-zero reference. The error values are constant within each plotted trace and were estimated from the standard deviation of reference/pre-pump points used in the plotting scripts.

The Fig1c sheet contains 37 time-delay points from approximately -0.300 ps to 9.299 ps. The Fig1d sheet contains 36 time-delay points from approximately -0.431 ps to 9.070 ps.

Fig1cd_insets_data.xlsx contains the polarization-state coordinates plotted in the Poincare-sphere inset. The workbook has one sheet, Poincare_data, with six plotted polarization states:

• Fig.1c_inset_redcircle: S0Right_800
• Fig.1c_inset_bluecircle: S0Left_800
• Fig.1c_inset_redctriangle: S0Right_trXRD
• Fig.1c_inset_bluetriangle: S0Left_trXRD
• Fig.1c_inset_reddiamond: S0Right_MIR
• Fig.1c_inset_bluediamond: S0Left_MIR

The columns are:

• Label: marker label used in the plotted inset.
• unnamed second column: polarization-state name.
• s1: normalized Stokes coordinate S1/S0.
• s2: normalized Stokes coordinate S2/S0.
• s3: normalized Stokes coordinate S3/S0.

The normalized Stokes coordinates locate each pump polarization state on the Poincare sphere. Positive and negative s3 values correspond to opposite circular/elliptical handedness. The 800 nm and MIR entries correspond to the optical pump conditions used for the time traces in Fig. 1c and Fig. 1d, respectively. The trXRD entries provide comparison polarization states from the related trXRD study (https://doi.org/10.1103/7ctk-h28x) used in the inset.

ReadMe.txt is the short original note included with the data package. The present README expands that note for Dryad submission.

No special missing-data code is used in these files. Empty cells, if encountered, should be treated as not applicable rather than numerical zero.

Sharing/Access information

Links to other publicly accessible locations of the data:

• n/a

Data was derived from the following sources:

• The UED image and pump-probe intensity traces were derived from ultrafast electron diffraction measurements performed for the corresponding Comment (https://doi.org/10.1103/p5d8-548h).
• The polarization-state data include measured pump polarization states for the present work (https://doi.org/10.1103/p5d8-548h). and comparison trXRD polarization states from https://doi.org/10.1103/7ctk-h28x.