Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 90: Electronic structure of surfaces: Spectroscopy, surface states IV
O 90.5: Vortrag
Donnerstag, 15. März 2018, 11:30–11:45, MA 042
Origin of Surface States in ZrSiS and related compounds — •Andreas Topp1, Raquel Queiroz1,2, Leslie M. Schoop1,3, and Christian R. Ast1 — 1Max Planck Institute for Solid State Research, Stuttgart, DEU-70569 — 2Weizmann Insitute of Science, Rehovot, ISR-7610001 — 3Department of Chemistry, Princeton University, Princeton, USA-08544
Three-dimensional Dirac semimetals, which accomodate massless Dirac and Weyl fermions, show exotic physical properties, e.g. an extremly high mobility and giant magnetoresistance. Compounds that comprise nonsymmorphic symmetries are especially interesting as the band crossings that are protected by the symmetry, are not effected by SOC. ZrSiS, hosting a square lattice of Si atoms, has shown normal, as well as, nonsymmorphically protected 3D Dirac crossings at and close to the Fermi level [1]. ARPES measurements showed additional surface states crossing the bulk bands, which do not fit in the current scheme of surface states. Here, we analyze their origin by comparing ARPES data with DFT and tight-binding calculations. We present the idea of a selective symmetry breaking through the surface that lifts the nonsymmorphic degeneracy at the X point and leads to the formation of these surface states.
[1] L. M. Schoop et al., Nat. Comm. 7, 11696 (2016).