Magnetoplasmons in magic-angle twisted bilayer graphene

TL;DR

This paper investigates how external magnetic fields and charge doping influence magnetoplasmon excitations in magic-angle twisted bilayer graphene, revealing unique dispersion features and potential for plasmonic applications.

Contribution

It demonstrates the distinctive magnetoplasmon dispersion in MATBLG under magnetic fields and charge doping, highlighting features not previously explored.

Findings

Presence of pronounced single magnetoplasmon modes near charge neutrality

Charge doping induces multiple strong-weight magnetoplasmons

Magnetoplasmon properties are significantly affected by transferred momentum and doping

Abstract

The magic-angle twisted bilayer graphene (MATBLG) has been demonstrated to exhibit exotic physical properties due to the special flat bands. However, exploiting the engineering of such properties by external fields is still in it infancy. Here we show that MATBLG under an external magnetic field presents a distinctive magnetoplasmon dispersion, which can be significantly modified by transferred momentum and charge doping. Along a wide range of transferred momentum, there exist special pronounced single magnetoplasmon and horizontal single-particle excitation modes near charge neutrality. We provide an insightful discussion of such unique features based on the electronic excitation of Landau levels quantized from the flat bands and Landau damping. Additionally, charge doping leads to peculiar multiple strong-weight magnetoplasmons. These characteristics make MATBLG a favorable candidate for plasmonic devices and technology applications.