Feature-rich plasmon excitations in sliding bilayer graphene

TL;DR

This paper investigates the complex plasmon excitations in sliding bilayer graphene using a tight-binding model combined with a modified random-phase approximation, revealing diverse behaviors influenced by layer shifts and doping levels.

Contribution

It introduces a detailed theoretical analysis of plasmon modes in sliding bilayer graphene considering electron-electron interactions and layer shifts, providing predictions for experimental validation.

Findings

Two types of plasmon modes are identified during doping variation.

Layer shifts significantly affect excitation behaviors.

Theoretical results are verifiable by high-resolution experiments.

Abstract

The tight-binding model is closely associated with the modified layer-based random-phase approximation to thoroughly investigate the electron-electron interactions in sliding bilayer graphene. The Coulomb interactions and intralayer and interlayer atomic interactions dominate the collective and electron-hole excitations. The unusual energy bands are directly reflected in the diverse transferred momentum-frequency phase diagrams. In general, there exist two kinds of plasmon modes during the variation of the doping level in sliding bilayer graphene, being accompanied with the complicated intraband and interband single-particle excitations. The excitation behaviors are greatly diversified by the relative shift between two graphene layers. The theoretical predictions can be verified by high-resolution experimental examinations.