@article{HansmannParraghToschietal.2014,
  author    = {Hansmann, P. and Parragh, N. and Toschi, A. and Sangiovanni, G. and Held, K.},
  title     = {Importance of d-p Coulomb interaction for high T-C cuprates and other oxides},
  series = {New Journal of Physics},
  volume    = {16},
  journal   = {New Journal of Physics},
  number    = {33009},
  issn      = {1367-2630},
  doi       = {10.1088/1367-2630/16/3/033009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117165},
  year      = {2014},
  abstract  = {Current theoretical studies of electronic correlations in transition metal oxides typically only account for the local repulsion between d-electrons even if oxygen ligand p-states are an explicit part of the effective Hamiltonian. Interatomic interactions such as U-pd between d- and (ligand) p-electrons, as well as the local interaction between p-electrons, are neglected. Often, the relative d-p orbital splitting has to be adjusted 'ad hoc' on the basis of the experimental evidence. By applying the merger of local density approximation and dynamical mean field theory to the prototypical case of the three-band Emery dp model for the cuprates, we demonstrate that, without any 'ad hoc' adjustment of the orbital splitting, the charge transfer insulating state is stabilized by the interatomic interaction U-pd. Our study hence shows how to improve realistic material calculations that explicitly include the p-orbitals.},
  language  = {en}
}
@article{GabelPickemScheidereretal.2022,
  author    = {Gabel, Judith and Pickem, Matthias and Scheiderer, Philipp and Dudy, Lenart and Leikert, Berengar and Fuchs, Marius and St{\"u}binger, Martin and Schmitt, Matthias and K{\"u}spert, Julia and Sangiovanni, Giorgio and Tomczak, Jan M. and Held, Karsten and Lee, Tien-Lin and Claessen, Ralph and Sing, Michael},
  title     = {Toward Functionalized Ultrathin Oxide Films: The Impact of Surface Apical Oxygen},
  series = {Advanced Electronic Materials},
  volume    = {8},
  journal   = {Advanced Electronic Materials},
  number    = {4},
  issn      = {2199-160X},
  doi       = {10.1002/aelm.202101006},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318914},
  year      = {2022},
  abstract  = {Thin films of transition metal oxides open up a gateway to nanoscale electronic devices beyond silicon characterized by novel electronic functionalities. While such films are commonly prepared in an oxygen atmosphere, they are typically considered to be ideally terminated with the stoichiometric composition. Using the prototypical correlated metal SrVO\(_{3}\) as an example, it is demonstrated that this idealized description overlooks an essential ingredient: oxygen adsorbing at the surface apical sites. The oxygen adatoms, which are present even if the films are kept in an ultrahigh vacuum environment and not explicitly exposed to air, are shown to severely affect the intrinsic electronic structure of a transition metal oxide film. Their presence leads to the formation of an electronically dead surface layer but also alters the band filling and the electron correlations in the thin films. These findings highlight that it is important to take into account surface apical oxygen or—mutatis mutandis—the specific oxygen configuration imposed by a capping layer to predict the behavior of ultrathin films of transition metal oxides near the single unit-cell limit.},
  language  = {en}
}