1 Physics Institute II, University of Cologne, D-50937 Köln, Germany

2 Institute for Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany

3 Peter Grünberg Institut (PGI-1), Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Publication date: Jan 30, 2025

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Description

Among the family of topological superconductors derived from Bi₂Se₃, Cu_x(PbSe)₅(Bi₂Se₃)₆ is unique in its surface termination of a single quintuple layer (QL) of the topological insulator (TI) Bi₂Se₃ on an ordinary insulator PbSe. Here, we report a combined scanning tunneling microscopy (STM) and density functional theory (DFT) characterization of the cleaved surface of the parent compound (PbSe)₅(Bi₂Se₃)₆ (PSBS). Interestingly, the potential disorder due to the random distribution of native defects is only Γ ∼ 4 meV, among the smallest reported for TIs. Performing high-resolution quasiparticle interference imaging (QPI) near the Fermi energy (E−E_F = −1 eV to 0.6 eV) we reconstruct the dispersion relation of the dominant spectral feature and our ab initio calculations show that this surface feature originates from two bands with Rashba-like splitting due to strong spin-orbit coupling and inversion symmetry breaking. Moreover, a small hexagonal distortion of the calculated Fermi surface is seen in the full momentum space distribution of the measured scattering data. Interestingly, the scattering pattern transforms into a flower-like shape with suppressed intensity along the ΓK direction, at lower energies. However, this change is not due to the forbidden backscattering in the topological surface state in Bi₂Se₃ but the threefold symmetry of the scattering potential itself. This dataset contains the experimental and theoretical data of this work.

Materials Cloud sections using this data

Files

File name	Size	Description
README.md MD5md5:74680bffa8b0bd9e91346a7ed1992dc1	1.4 KiB	Description of the dataset
structure.cif MD5md5:817bb7ac64d19044ebf356bdfe4bc3bd	12.0 KiB	Relaxed crystal structure of PSBS used in DFT calculations
data_spin_polarized.zip MD5md5:8e49f949ceb2ea9381e3f869d2a4c6fd	1.4 MiB	Spin-polarized DFT bandstructure presented in Fig. 8
requirements.txt MD5md5:799fdd4415f21b4aa27058f8d90d3c69	4.5 KiB	Python requirements file for the used environment
figs_theory1_bandstuc_model.ipynb MD5md5:cdbf402e2cf44cdda82b733356a21ff5	540.8 KiB	Plotting of bandstructure and model fitting to DFT data
figs_theory2_JDOS.ipynb MD5md5:5e70c82ba43aba8ec23b75b979bf4dd3	484.1 KiB	Plotting of JDOS from DFT constant energy contours
figs_theory3_PB_Bi_defect_Bi2Se3.ipynb MD5md5:9da24992ce3f36ad337940992a7c43f7	145.4 KiB	Plotting of QPI around Pb anti-site defect in Bi2Se3
export_QPI.aiida MD5md5:eb2714c39e66ce0b63cf1df7e6a4da4e Open this AiiDA archive on renkulab.io (https://renkulab.io/)	74.8 MiB	AiiDA export file of QPI analysis of Pb:Bi anti site defects in Bi2Se3
data_bandstruc_JDOS.zip MD5md5:eff77539b85d1d7c0f84e22c713b33dc	34.1 MiB	Data for bandstructure and JDOS analysis
ExperimentalData.zip MD5md5:95ce51c78b237467618df18a793086fb	126.3 MiB	Experimental data underlying all figures given in .csv or .txt file format. Furthermore, the raw experimental data files are provided.

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