Anisotropic low-energy plasmon excitations in doped graphene: An ab initio study
Artikel i vetenskaplig tidskrift, 2011

Low-energy electronic excitations in free-standing graphene (gr) and gr(2 x 2)/K interface have been studied based on ab initio band structure and linear-response theory. For pristine graphene, the calculated linear dispersion of collective interband transitions around the Dirac cone is in good agreement with experiments. At the gr/K interface, in addition to the doping-enhanced linear mode, a nonlinear plasmon develops with increasing momentum transfers along the Gamma K direction. Using a model-doped freestanding graphene, we revealed that the nonlinear mode originates from the anisotropic band dispersion at the Fermi level, and its collectivity emerges as the carrier density increases. These findings have implications for measurements of electronic excitations in metal-supported graphene sheet.

Time-dependent

electron-gas

Surfaces and interfaces

Graphene

Dielectric response

density functional theory

dynamics

Författare

Y. Gao

Institute of Physics Chinese Academy of Sciences

Zhe Yuan

Chalmers, Teknisk fysik, Material- och ytteori

Solid State Communications

0038-1098 (ISSN)

Vol. 151 14-15 1009-1013

Styrkeområden

Nanovetenskap och nanoteknik

Materialvetenskap

Ämneskategorier

Fysik

Den kondenserade materiens fysik

Fundament

Grundläggande vetenskaper

DOI

10.1016/j.ssc.2011.05.001