Coulomb interaction and electron-hole asymmetry in cyclotron resonance of bilayer graphene in high magnetic field

TL;DR

This paper investigates how Coulomb interactions and electron-hole asymmetry influence cyclotron resonance in bilayer graphene under high magnetic fields, revealing field-dependent energy splittings.

Contribution

It introduces a comprehensive analysis of inter-Landau-level transitions considering next-nearest-neighbor effects, asymmetries, and Coulomb interactions within the Hartree-Fock framework.

Findings

Energy splitting depends on magnetic field strength.

At low fields, asymmetry is due to electron-hole differences.

At high fields, Coulomb interaction dominates the splitting.

Abstract

Inter-Landau-level transitions in the bilayer graphene at high perpendicular magnetic field at the filling-factor v<<1 have been studied. The next-nearest-neighbor transitions, energy difference between dimer and non-dimer sites and layer asymmetry are included. The influence of Coulomb interaction is taken into account. The magnetoplasmon excitations in bilayer graphene at small momenta are considered in the frame of the Hartree-Fock approximation. It is shown that asymmetry in cyclotron resonance of clean bilayer graphene depends on magnetic field. At lower magnetic fields the energy splitting in the spectrum is due to electron-hole one-particle asymmetry, at higher magnetic fields the energy splitting in the spectrum is due to Coulomb interaction. For the fullsymmetric case with half-filled zero-energy levels the energy splitting proportional to the energy of Coulomb interaction is found both for bilayer and monolayer graphene.