Plasmons in Dimensionally Mismatched Coulomb Coupled Graphene Systems

Area of Science:

• Condensed matter physics
• Materials science
• Nanotechnology

Background:

• Graphene nanoribbons and doped monolayer graphene are key materials in nanoscale electronics.
• Plasmon dispersion relations are crucial for understanding light-matter interactions in these systems.
• Interactions between coupled 1D and 2D systems can lead to novel phenomena.

Purpose of the Study:

• To investigate the impact of interlayer Coulomb coupling on plasmon dispersion relations in metallic armchair graphene nanoribbons and doped monolayer graphene.
• To analyze the resulting plasmon branches and their unique characteristics.
• To explore the potential applications of the observed plasmon structures.

Main Methods:

• Theoretical calculation of the plasmon dispersion relation.
• Analysis of Coulomb coupling effects between graphene layers.
• Investigation of the structure factor and its dependence on plasmon wavelength.

Main Results:

• The crossing of plasmon curves in uncoupled systems is split into distinct lower and upper plasmon branches due to interlayer Coulomb coupling.
• The upper plasmon branch displays unusual behavior, with defined endpoints at finite momentum (q).
• The structure factor exhibits either single or double peak behavior, influenced by the plasmon wavelength.

Conclusions:

• Interlayer Coulomb coupling fundamentally alters plasmon behavior in coupled graphene systems.
• The newly identified plasmon structure offers tunable properties by adjusting system parameters.
• This research provides insights relevant to recent experiments and opens avenues for plasmonic applications.