Data from: A table-top few-femtosecond broadband extreme-ultraviolet absorption spectrometer with cryogenic cooling
Data files
Sep 17, 2026 version files 1.84 MB
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Archive.zip
1.83 MB
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README.md
6.93 KB
Abstract
This dataset accompanies the article A table-top few-femtosecond broadband extreme-ultraviolet absorption spectrometer with cryogenic cooling, which presents a table-top cryogenic ultrafast broadband XUV absorption spectroscopy (c-UBXAS) beamline designed for temperature-dependent and time-resolved investigations of quantum materials. The instrument combines a broadband high-harmonic generation source spanning 22–73 eV with automated image registration and cryogenic sample control down to 20 K, enabling element-specific measurements under both equilibrium and nonequilibrium conditions. The beamline provides sub-50-meV energy resolution and a routine 10-fs instrument response function while maintaining the long-term stability required for extended, ultrasensitive measurements. Benchmark measurements on the van der Waals multiferroic NiI2 resolve temperature-dependent spectral evolution across its magnetic phase transitions and element-specific transient responses in the femtosecond regime.
The repository contains the numerical source data underlying the beamline characterization and NiI2 measurements reported in the article, including spectral, temporal, stability, temperature-dependent, and pump-probe datasets together with associated fit data where applicable. These data can be reused to reproduce the reported figures, benchmark XUV spectroscopy analysis methods, and support further analysis of ultrafast and temperature-dependent XUV measurements.
Description of the data repository:
This data repository contains all numerical data used to generate the figures shown in the paper, “A table-top few-femtosecond broadband extreme-ultraviolet absorption spectrometer with cryogenic cooling.” The data are provided in Archive.zip, which is organized into folders corresponding to individual figures. Each folder and its associated data files are described below. Figures 1–7 consist of photographs, schematics, and three-dimensional renderings of the experimental setup and therefore do not have associated numerical source data. Unless otherwise noted, all figures were generated using Igor Pro (WaveMetrics). All numerical data are provided as comma-separated value (.csv) files and can be opened using standard spreadsheet or data-analysis software. Igor Pro is not required to access the data.
Archive: Archive.zip
Folder: Fig_8
Description: Sample stage corrections (X and Z displacements) during temperature cycling of NiI2
File: Fig_8.csv
Description: contains the sample temperature and the relative sample displacements along the X and Z directions, referenced to the sample position at approximately 220 K.
Variables:
Temperature
Relative SampleX
Relative SampleZ
Folder: Fig_9
Description: Generated high-harmonic-generation (HHG) flux density as a function of photon energy
File: Fig_9.csv
Description: contains the photon energy and the corresponding XUV flux density
Variables:
Energy, eV
Flux density
Folder: Fig_10
Description: Transmitted XUV spectra of He, Ne, and Ar used to characterize the energy resolution of the XUV spectrometer
Files: Fig_10_Ar.csv, Fig_10_He.csv, Fig_10_Ne.csv
Description: contain the wavelength and corresponding transmitted XUV intensity
Variables:
Wavelength, nm
Transmitted Intensity
Files: Fig_10_Ar_fit.csv, Fig_10_He_fit.csv, Fig_10_Ne_fit.csv
Description: Provide associated fits. Contain the wavelength and fitted intensity
Variables:
Wavelength, nm
Intensity
Folder: Fig_11
Description: Transient XUV transmission data of Ne used to characterize the temporal resolution of the c-UBXAS setup
File: Fig_11a_static.csv
Description: contains the photon energy and normalized static XUV signal
Variables:
photon energy, eV
normalized signal
File: Fig_11a_transient.csv
Description: the first column gives the photon energy (eV), the first row gives the pump–probe delay time (fs), and the remaining matrix elements give the transient transmission change.
File: Fig_11b_time_trace.csv
Description: contains the pump–probe delay time and normalized transient transmission change, together with a separate delay-time axis and the corresponding fitted response
Variables:
delay time, fs
normalized transmission change
delay time, fs
fit
Folder: Fig_12
Description: Long-term stability measurements of the c-UBXAS beamline over 16 hours, including the raw XUV spectra, extracted Ar resonance position, and integrated XUV intensity
File: Fig_12_a_raw_spectra.csv
Description: the first column gives the CCD pixel number, the first row gives the laboratory acquisition time (hr), and the remaining matrix elements give the XUV intensity at each pixel and acquisition time
File: Fig_12_a_inset.csv
Description: contains the CCD pixel number and XUV intensity for the enlarged Ar spectral feature
Variables:
Pixel number
Intensity
Folder: Fig_13
Description: Ne transient absorption measurements acquired before and after a 16-hour scan to characterize the long-term temporal stability of the c-UBXAS beamline
File: Fig_13.csv
Description: contains the pump–probe delay time and transient signal measured before and after the 16-hour scan, together with the corresponding delay-time axes and fitted transient responses
Variables:
delay time, fs
before_fit and after fit
Folder: Fig_14
Description: Static XUV absorption spectra of NiI2 obtained using raster-scan and two-point measurements.
File: Fig_14.csv
Description: contains the photon energy and corresponding XUV absorption for the raster-scan measurement, followed by the photon energy and XUV absorption for the two-point measurement
Variables:
Photon energy, eV
absorption_raster
Photon energy, eV
absorption_2pt
Folder: Fig_15
Description: Temperature-dependent XUV absorption spectra of NiI2 during a 200–20–200 K cooling–warming cycle, together with the extracted peak positions and linewidths
File: Fig_15_a.csv
Description: the first column gives the photon energy (Photon energy, eV), columns 1–59 correspond to sequential spectrum indices during the temperature cycle, and the remaining matrix elements give the XUV absorption spectra
Variables:
Photon energy, eV
1-59: sequential spectrum indices during the temperature cycle
Files: Fig_15_b.csv, Fig_15_c.csv, Fig_15_d.csv
Description: contain the sample temperature peak position, and associated fitting uncertainty for absorption features 1, 2, and 3, respectively.
Variables:
Peak position, eV
error, eV
Files: Fig_15_e.csv, Fig_15_f.csv
Description: contain the sample temperature, peak width, and associated fitting uncertainty for absorption features 1 and 2, respectively.
Variables:
Temperature, K
Peak width, eV
error, eV
Folder: Fig_16
Description: Temperature-dependent transient XUV absorption measurements of NiI2 at 300 K and 23 K following photoexcitation
File: Fig_16_a_static.csv
Description: contains the photon energy and static XUV absorption shown for reference
Variables:
Photon energy, eV
absorption
Files: Fig_16_a.csv, Fig_16_b.csv
Description: the first column gives the photon energy, the first row gives the pump–probe delay time, and the remaining matrix elements give the transient transmission change measured at 300 K and 23 K, respectively
Variables:
eV
fs
Files: Fig_16_c.csv, Fig_16_d.csv, Fig_16_e.csv
Description: contain the extracted transient signals at 300 K and 23 K and their associated fits for the 48.67–49.23 eV, 49.30–49.78 eV, and 64.46–65.55 eV spectral regions, respectively. Each file provides the experimental pump–probe delay time (delay time, fs), transient signal at 300 K and 23 K, separate delay-time axes for the fits (delay time fit, fs), and the corresponding fitted responses (300 K fit and 23 K fit).
Variables:
delay time (fs)
300K
delay time fit (fs)
300 K fit
delay time (fs)
23 K
delay time fit (fs)
23 K fit