Generation and morphing of plasmons in graphene superlattices

TL;DR

This paper develops a theoretical framework for understanding and controlling plasmon excitations in graphene-hBN moiré superlattices, revealing their potential for advanced plasmonic applications.

Contribution

It introduces a novel theory of plasmon spectra in graphene superlattices, highlighting active control mechanisms beyond electrostatic gating.

Findings

Graphene-hBN stacks support tunable plasmon modes.

Moiré patterns significantly modify plasmon dispersion.

Control of plasmon modes via crystallographic adjustments is possible.

Abstract

Recent experimental studies on graphene on hexagonal Boron Nitride (hBN) have demonstrated that hBN is not only a passive substrate that ensures superb electronic properties of graphene's carriers, but that it actively modifies their massless Dirac fermion character through a periodic moir\'e potential. In this work we present a theory of the plasmon excitation spectrum of massless Dirac fermions in a moir\'e superlattice. We demonstrate that graphene-hBN stacks offer a rich platform for plasmonics in which control of plasmon modes can occur not only via electrostatic gating but also by adjusting e.g. the relative crystallographic