@article{FiedlerElKarehEremeevetal.2014,
  author    = {Fiedler, Sebastian and El-Kareh, Lydia and Eremeev, Sergey V. and Tereshchenko, Oleg E. and Seibel, Christoph and Lutz, Peter and Kokh, Konstantin A. and Chulkov, Evgueni V. and Kuznetsova, Tatyana V. and Grebennikov, Vladimir I. and Bentmann, Hendrik and Bode, Matthias and Reinert, Friedrich},
  title     = {Defect and structural imperfection effects on the electronic properties of BiTeI surfaces},
  series = {New Journal of Physics},
  volume    = {16},
  journal   = {New Journal of Physics},
  number    = {075013},
  issn      = {1367-2630},
  doi       = {10.1088/1367-2630/16/7/075013},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119467},
  year      = {2014},
  abstract  = {The surface electronic structure of the narrow-gap seminconductor BiTeI exhibits a large Rashba-splitting which strongly depends on the surface termination. Here we report on a detailed investigation of the surface morphology and electronic properties of cleaved BiTeI single crystals by scanning tunneling microscopy, photoelectron spectroscopy (ARPES, XPS), electron diffraction (SPA-LEED) and density functional theory calculations. Our measurements confirm a previously reported coexistence of Te- and I-terminated surface areas originating from bulk stacking faults and find a characteristic length scale of ~100 nm for these areas. We show that the two terminations exhibit distinct types of atomic defects in the surface and subsurface layers. For electronic states resided on the I terminations we observe an energy shift depending on the time after cleavage. This aging effect is successfully mimicked by depositon of Cs adatoms found to accumulate on top of the I terminations. As shown theoretically on a microscopic scale, this preferential adsorbing behaviour results from considerably different energetics and surface diffusion lengths at the two terminations. Our investigations provide insight into the importance of structural imperfections as well as intrinsic and extrinsic defects on the electronic properties of BiTeI surfaces and their temporal stability.},
  language  = {en}
}
@article{ElKarehBihlmayerBuchteretal.2014,
  author    = {El-Kareh, Lydia and Bihlmayer, Gustav and Buchter, Arne and Bentmann, Hendrik and Bl{\"u}gel, Stefan and Reinert, Friedrich and Bode, Matthias},
  title     = {A combined experimental and theoretical study of Rashba-split surface states on the ( √3x√3) Pb/Ag (111)R30° surface},
  doi       = {doi:10.1088/1367-2630/16/4/045017},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112786},
  year      = {2014},
  abstract  = {We report on a combined low-temperature scanning tunneling spectroscopy (STS), angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) investigation of the ( √3x√3) Pb/Ag (111)R30° surface alloy which provides a giant Rashba-type spin splitting. With STS we observed spectroscopic features that are assigned to two hole-like Rashba-split bands in the unoccupied energy range. By means of STS and quantum interference mapping we determine the band onsets, splitting strengths, and dispersions for both bands. The unambiguous assignment of scattering vectors is achieved by comparison to ARPES measurements. While intra-band scattering is found for both Rashba bands, inter-band scattering is only observed in the occupied energy range. Spin- and orbitally-resolved band structures were obtained by DFT calculations. Considering the scattering between states of different spin- and orbital character, the apparent deviation between experimentally observed scattering events and the theoretically predicted spin polarization could be resolved.},
  language  = {en}
}