Regensburg 2013 – wissenschaftliches Programm

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

HL: Fachverband Halbleiterphysik

HL 28: Poster Session: Graphen; Transport properties; Transport in high magnetic fields / Quantum Hall effect; Metal-semiconductor hybrid systems

HL 28.7: Poster

Montag, 11. März 2013, 16:00–20:00, Poster A

Electronic and optical properties of bilayer-array-embedded graphene — •Hengyi Xu and Thomas Heinzel — Heinrich-Heine-Universität Düsseldorf, Germany

The coexistence of monolayer and bilayer graphene is widely found in graphene samples, like large-scale monolayer/bilayer interfaces obtained from mechanical exfoliation or small-scale interfaces due to some graphite atoms sitting on graphene layers in epitaxial growth. These structures show a rich phenomenology and may provide some new possibilities for device applications.

In this work, we focus on structures with additional carbon atoms located on top of a monolayer graphene, thereby forming a regular hexagonal array of monolayer/bilayer quantum dots. The implementation of such structures seems to be rather plausible via the method of epitaxial growth. The electronic and optical transport properties of the periodic monolayer/bilayer interface are systemically studied with the Kubo formalism. The density of states as well as the electronic and optical conductivity are calculated by solving the time-dependent Schrödinger equation. It is found that the monolayer/bilayer interface array induces midgap states and suppresses the transmission in vicinity of Dirac points. Interface scattering has also a far-reaching impact on the Landau levels and Hall conductivity. In addition, the optical conductivity of such systems exhibits some extra peaks at the low frequencies due to the renormalization of density of states.