%0 Journal Article
%A Bagchi, Mahasweta
%A Rüssmann, Philipp
%A Bihlmayer, Gustav
%A Blügel, Stefan
%A Ando, Yoichi
%A Brede, Jens
%T Quasiparticle interference on the surface of Bi 2 Se 3 -terminated (PbSe) 5 ( Bi 2 Se 3 ) 6
%J Physical review / B
%V 112
%N 4
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M FZJ-2025-03066
%P 045411
%D 2025
%X Among the family of topological superconductors derived from Bi 2 Se 3 , Cux (PbSe) 5 (Bi 2 Se 3 ) 6 is unique in its surface termination of a single quintuple layer (QL) of the topological insulator (TI) Bi 2 Se 3 on an ordinaryinsulator 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 (Bi 2 Se 3 ) 6 (PSBS). Interestingly,the potential disorder due to the random distribution of native defects is only  ∼ 4 meV, comparable to the smallest reported for TIs. Performing high-resolution quasiparticle interference imaging (QPI) near the Fermienergy (E − EF = −1 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 dueto strong spin-orbit coupling and inversion symmetry breaking. Moreover, only a small hexagonal distortion of the calculated Fermi surface is seen in the full momentum space distribution of the measured scattering data.Nevertheless, the scattering pattern at lower energies transforms into a flowerlike shape with suppressed intensity along the K direction. We show that this effect is not due to the forbidden backscattering in the spin-momentumlocked surface state in Bi 2 Se 3 but reflects the threefold symmetry of the scattering potential.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001539380900006
%R 10.1103/h8v9-sl53
%U https://juser.fz-juelich.de/record/1044177