Mapping Unoccupied Electronic States of Freestanding Graphene by Angle-Resolved Low-Energy Electron Transmission

Autor: Wicki, Flavio, Longchamp, Jean-Nicolas, Latychevskaia, Tatiana, Escher, Conrad, Fink, Hans-Werner
Rok vydání: 2016
Předmět:
Zdroj: Physical Review B, Volume 94, Issue 7, 075424 (2016)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.94.075424
Popis: We report angle-resolved electron transmission measurements through freestanding graphene sheets in the energy range of 18 to 30 eV above the Fermi level. The measurements are carried out in a low-energy electron point source microscope, which allows simultaneously probing the transmission for a large angular range. The characteristics of low-energy electron transmission through graphene depend on its electronic structure above the vacuum level. The experimental technique described here allows mapping the unoccupied band structure of freestanding two-dimensional materials as a function of energy and probing angle, respectively in-plane momentum. Our experimental findings are consistent with theoretical predictions of a resonance in the band structure of graphene above the vacuum level [V. U. Nazarov, E. E. Krasovskii, and V. M. Silkin, Physical Review B 87, 041405 (2013)].
Databáze: arXiv