Coulomb excitations in ABC-stacked trilayer graphene

Abstract

The layer-based random-phase approximation is further developed to investigate electronic excitations in tri-layer ABC-stacked graphene. All the layer-dependent atomic interactions and Coulomb interactions are included in the dynamic charge screening. There exist rich and unique (momentum, frequency)-excitation phase diagrams, in which the complex single-particle excitations and five kinds of plasmon modes, are dominated by the unusual energy bands and doping carrier densities.The latter frequently experience the significant Landau damping due to the former, leading to the coexistence/destruction in the energy loss spectra. Specifically, the dispersion of the only acoustic plasmon in pristine case is dramatically changed from linear into quadratic even at very low doping.

Unusual features of nitrogen substitutions in silicene

“…They are very suitable for identifying the abundant special structures in the density of states due to the various numbers of layers and stacking congurations of few-layer graphene systems, such as monolayer graphene, 60 AB bilayer and trilayer stackings, 61 twisted bilayer graphenes, 62 and ABC-and AAB-stacked trilayer graphene systems. 63,64 Very interestingly, direct combinations of SP-STM and SP-STS are capable of thoroughly examining the spininduced magnetic properties. To date, the former is successful in observing magnetic domains and domain-wall structures with a high spatial resolution of 10 nm; 65 furthermore, the latter can distinguish between metallic and semiconducting ferromagnetism.…”

Coulomb Excitations and Decays in Graphene-Related Systems

“…It has been very successfully in understanding the diverse electronic excitation spectra in layered systems, e.g., AA-, [21][22][23][24] AB- [24,27,28] and ABC-stacked graphenes. [29] The magnetoplasmon is discussed in this book by the development of the modified RPA and the generalized Peierls tight-binding model. [30][31][32][33] It is very suitable for studying the inter-landau-level (inter-LL), single-particle excitations and magneto-plasmon modes.…”

“…[2,32,71] Although the ABC stacking is a semimetal with a very low free carrier density, it is predicted to exhibit the low-frequency plasmom mode closely related to the localized states. [29] Furthermore, the novel momentum dependence of the pristine plasmons is never observed in other stackings. On the other hand, the doping carriers in extrinsic systems will strongly compete with the original surface states.…”

“…The similar effects are revealed in the trilayer ABA and ABC stackings. [29,69] This work will cover the complete results in the E z -enriched excitation spectra of the ABA, ABC and AAB stackings.…”

“…Such electronic wave functions are ascribed to the special surface states due to the main contributions of carbon atoms in the outmost two layers [2,32,71]. Although the ABC stacking is a semimetal with a very low free carrier density, it is predicted to exhibit the low-frequency plasmom mode closely related to the localized states [29]. Fur-comparison between the tight-binding model and VASP calculations in the low-lying energy bands [84,85].…”