Superluminal plasmons with resonant gain in population inverted bilayer graphene

TL;DR

This paper explores the theoretical potential for superluminal plasmons with resonant optical gain in AB-stacked bilayer graphene possessing a tunable bandgap exceeding optical phonon energies.

Contribution

It introduces the concept of resonant optical gain and superluminal plasmons in bilayer graphene with a tunable bandgap, highlighting new physical phenomena.

Findings

Resonant optical gain near the asymmetry gap in bilayer graphene.

Amplification of plasmons with negative group velocity.

Presence of superluminal effects and directional leaky modes.

Abstract

AB-stacked bilayer graphene with a tunable electronic bandgap in excess of the optical phonon energy presents an interesting active medium, and we consider such theoretical possibility in this work. We argue the possibility of a highly resonant optical gain in the vicinity of the asymmetry gap. Associated with this resonant gain are strongly amplified plasmons, plasmons with negative group velocity and superluminal effects, as well as directional leaky modes.