Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 51: Poster: Electronic Structure of Surfaces: Spectroscopy, Surface States

O 51.8: Poster

Dienstag, 13. März 2018, 18:15–20:30, Poster B

Quantifying the charge density wave properties in VSe₂ — •Timo Knispel¹, Wouter Jolie^1,2, Niels Ehlen¹, Konstantin Nikonov¹, Carsten Busse^2,3, Alexander Grüneis¹, and Thomas Michely¹ — ¹II. Physikalisches Institut, Universität zu Köln, Germany — ²Institut für Materialphysik, Westfälische Wilhelms-Universität — ³Department Physik, Universität Siegen

We use scanning tunneling microscopy and spectroscopy (STS) to image the charge density wave (CDW) at the surface of VSe₂ and to probe its local density of states. Angle-resolved photoemission and tight-binding calculations are used to link the main features observed in STS spectra to contributions of the p-like and d-like bands of VSe₂. A transparent method to estimate the partial CDW gap based on STS spectra is provided. The estimated CDW gap of 26±6 meV is is in good agreement with the transition temperature of VSe₂, pointing to weak electron-phonon coupling. This leads to the conclusion that the Peierls model of Fermi surface nesting is applicable in this material. The role of defects is investigated, which reveals that the partial gap in the density of states and hence the CDW itself is extremely stable, though the periodic modulation and amplitude of the CDW on the surface are strongly perturbed.