The magnetic field particle-hole excitation spectrum in doped graphene and in a standard two-dimensional electron gas

TL;DR

This paper calculates and compares the particle-hole excitation spectrum in doped graphene and a standard 2D electron gas under various magnetic fields, highlighting differences in collective excitations and screening effects.

Contribution

It provides a detailed analysis of the magnetic field effects on the excitation spectrum in doped graphene versus a 2DEG, including electron-electron interactions within RPA.

Findings

Distinct collective modes identified in graphene and 2DEG

Magnetic field influences on plasmon and magneto-excitons characterized

Screening effects differ significantly between the two systems

Abstract

The particle-hole excitation spectrum for doped graphene is calculated from the dynamical polarizability. We study the zero and finite magnetic field cases and compare them to the standard two-dimensional electron gas. The effects of electron-electron interaction are included within the random phase approximation. From the obtained polarizability, we study the screening effects and the collective excitations (plasmon, magneto-excitons, upper-hybrid mode and linear magneto-plasmons). We stress the differences with the usual 2DEG.