Graphene plasmons: Impurities and nonlocal effects

Edge plasmons in graphene nanostructures

Plasmon modes in graphene are influenced by the unusual dispersion relation of the material. For bulk plasmons this results in a n1/4 dependence of the plasma frequency on the charge density, as opposed to the n1/2 dependence in two-dimensional electron gas (2DEG); yet, bulk plasmon dispersion in graphene follows a similar q1/2 behavior as for other two-dimensional materials. In this work we co...

Infrared Topological Plasmons in Graphene.

We propose a two-dimensional plasmonic platform-periodically patterned monolayer graphene-which hosts topological one-way edge states operable up to infrared frequencies. We classify the band topology of this plasmonic system under time-reversal-symmetry breaking induced by a static magnetic field. At finite doping, the system supports topologically nontrivial band gaps with mid-gap frequencies...

Nonlocal effects in the plasmons of nanowires and nanocavities excited by fast electron beams

The solutions of surface modes in cylindrical metallic wires and cavities are obtained within a nonlocal dielectric formalism. We compare the results with those obtained from standard local approaches. The specular reflection model is applied to describe the nonlocal potentials in the vicinity of the wires and cavities. The external probe exciting the surface plasmons are fast electron beams tr...

Simulating impurities and edges in graphene

Scattering of graphene plasmons by defects in the graphene sheet.

A theoretical study is presented on the scattering of graphene surface plasmons (GSPs) by defects in the graphene sheet they propagate in. These defects can be either natural (as domain boundaries, ripples, and cracks, among others) or induced by an external gate. The scattering is shown to be governed by an integral equation, derived from a plane wave expansion of the fields, which in general ...