Inter-band magnetoplasmons in mono- and bi-layer graphene

TL;DR

This paper investigates the collective excitations spectrum of Dirac electrons in mono- and bilayer graphene under a magnetic field, revealing unique oscillations and Berry's phase effects, and compares these with conventional 2DEG results.

Contribution

It provides analytical results for inter-Landau band plasmon spectrum in graphene, highlighting the effects of chirality and Berry's phase on oscillations.

Findings

SdH oscillations depend monotonically on magnetic field

Chiral quasiparticles lead to π and 2π Berry's phases

Comparison with conventional 2DEG shows distinct behaviors

Abstract

Collective excitations spectrum of Dirac electrons in mono and bilayer graphene in the presence of a uniform magnetic field is investigated. Analytical results for inter-Landau band plasmon spectrum within the self-consistent-field approach are obtained. SdH type oscillations that are a monotonic function of the magnetic field are observed in the plasmon spectrum of both mono- and bi-layer graphene systems. The results presented are also compared with those obtained in conventional 2DEG. The chiral nature of the quasiparticles in mono and bilayer graphene system results in the observation of $\pi$ and $2\pi$ Berry's phase in the SdH- type oscillations in the plasmon spectrum.