Octahedral rotations and defect-driven metallicity at the (001) surface of CaTiO3
Résumé
Defect-free CaTiO3 is a band insulator, but angle-resolved photoemission spectroscopy experiments have demonstrated the existence of a nanometer-thin two-dimensional electron system (2DES) at the (001)-oriented surface of this compound. Our ab initio study finds that while oxygen defects are the driving mechanism for the metallicity, tiltings and rotations of the oxygen octahedra significantly impact the electronic structure of the 2DES and its response to externally applied strain deformations. The low-energy conduction subbands have a mixed t2g−eg orbital character close to the center of the Brillouin zone. Good agreement with the experimental spectra is found for TiO2 surface divacancy configurations.
Domaines
Physique [physics]| Origine | Fichiers produits par l'(les) auteur(s) |
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