Work Description

Date: 21 January, 2025

Dataset Title: Dataset for: Large Exciton Binding Energy in a Bulk van der Waals Magnet from Quasi-1D Electronic Localization

Dataset Contact: Na Hyun Jo [email protected]

Dataset Creators
Name: Shane Smolenski
Email: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0002-7516-9316

Name: Ming Wen
Email: [email protected]
Institution: Department of Chemistry, University of Michigan
ORCID: https://orcid.org/0009-0000-4800-3874

Name: Qiuyang Li
Email: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0002-8192-3960

Name: Eoghan Downey
Email: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0009-0002-9102-3189

Name: Adam Alfrey
Email: [email protected]
Institution: Applied Physics Program, University of Michigan

Name: Wenhao Liu
Email: [email protected]
Institution: Department of Physics, The University of Texas at Dallas
ORCID: https://orcid.org/0000-0001-9757-1077

Name: Aswin L. N. Kondusamy
Email: [email protected]
Institution: Department of Materials Science and Engineering, The University of Texas at Dallas

Name: Aaron Bostwick
Email: [email protected]
Institution: Advanced Light Source, Lawrence Berkeley National Laboratory
ORCID: https://orcid.org/0000-0002-9008-2980

Name: Chris Jozwiak
Email: [email protected]
Institution: Advanced Light Source, Lawrence Berkeley National Laboratory
ORCID: https://orcid.org/0000-0002-0980-3753

Name: Eli Rotenberg
Email: [email protected]
Institution: Advanced Light Source, Lawrence Berkeley National Laboratory
ORCID: https://orcid.org/0000-0002-3979-8844

Name: Liuyan Zhao
Email: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0001-9512-3537

Name: Hui Deng
Emai: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0003-0629-3230

Name: Bing Lv
Email: [email protected]
Institution: Departments of Physics & Materials Science and Engineering, The University of Texas at Dallas
ORCID: https://orcid.org/0000-0002-9491-5177

Name: Dominika Zgid
Email: [email protected]
Institution: Department of Chemistry, University of Michigan
ORCID: https://orcid.org/0000-0003-4363-8285

Name: Emanuel Gull
Emai: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0002-6082-1260

Name: Na Hyun Jo
Email: [email protected]
Institution: Department of Physics, University of Michigan
ORCID: https://orcid.org/0000-0003-4065-6429

Research Overview:
The optical properties of the 2D magnet CrSBr were explored through photoluminescence/reflectance, angle-resolved photoemission spectroscopy, and self-consistent GW calculations. These data reveal a large exciton binding energy in bulk CrSBr that is attributed to localization arising from the quasi-1D electronic structure.

Methodology:
All angle-resolved photoemission spectroscopy (ARPES) measurements were performed at Beamline 7.0.2 (MAESTRO) of the Advanced Light Source. The beamline is equipped with a R4000 spectrometer with deflectors that enable data collection across the full Brillouin zone without moving the sample. Bulk CrSBr crystals were mounted on Cu pucks with Epotek H20E silver epoxy and cleaved in situ at vacuum better than 5×10−11 mbar. All measurements with fixed photon energy were performed with 83-84eV photons with linear horizontal polarization. The beam spot size was 15 µm x 15 µm. Paramagnetic measurements were performed at temperatures of 192K, 195K, and 195K for Sample 1, Sample 2, and Sample 3, respectively while antiferromagnetic measurements (SI Fig. S6) were performed on Sample 1 at a temperature of 97K. Potassium dosing experiments were performed by evaporating potassium onto the cleaved CrSBr surface insitu from a SAES getter source such that the sample was not moved from the measurement position. The ARPES data was corrected to remove the distortion from a straight slit, corrected to the Fermi level (via comparison with Cu in contact with the sample and through the use of core spectra), and corrected from angle to crystal momentum.

Reflection contrast (RC) and photoluminescence (PL) spectroscopies were conducted by real-space imaging of the sample. The sample was kept in a Montana Fusion system for temperature control. An objective lens with numerical aperture (NA) of 0.42 was used for both focusing and collection. A supercontinuum white light laser (NKT Photonics, SuperK) with a beam size of ~2 μm in diameter was used as the white-light source for RC measurements. A continuous-wave solid-state laser at 532 nm with a power of 100 μW and a beam size of ~2 μm in diameter was used as pump for PL measurements. The collected signals were detected by a Princeton Instruments spectrometer with a cooled charge-coupled camera.

File Inventory/Notes on the Files Contained Here:
Each file is labeled with the figure in which it corresponds to in the related publication. For Figures 2g and 2h, an additional label is included to refer to the sample and the dosing level (in electrons per unit cell - corresponds to values found in the paper and listed in the related figures). All data are stored in csv format.

PL/RC Data
The PL and RC data are located in one file, with columns for PL energy, PL intensity, RC energy, and RC intensity. Only Figure_1d conatins PL/RC data.

ARPES Data
ARPES intensity maps (energy dispersion and iso-energy plots) are shared in matrix form. In each file, the top row has the (negative) binding energy (E - EF where EF is the Fermi level) of each column. The leftmost column is labeling the momentum k for each row. The value in each other cell is the intensity for the momentum (given by the row) and binding energy (given by the column). Data for energy dispersion curves (EDCs) are shared in two columns, with the leftmost column being (negative) binding energy (E - EF) and the rightmost column is intensity. ARPES intensity maps are found in Figure_2a-d, all Fig_2h files, and Figure_4a while EDCs are found in all Fig_2g files. Note that for File 2h, the data provided are the original energy dispersion plots at various dosing levels that can be used to determine the band gap at each level.

Note that the data plotted in Figure 4c is derived from the data in Figures 2c and 2d.

Please reach out to the corresponding author for more details or for further data requests.