Negative Landau damping in bilayer graphene

TL;DR

This paper theoretically shows that coupled graphene sheets can exhibit negative Landau damping, enabling plasmon amplification and light emission in the mid-infrared range through drift-induced instabilities.

Contribution

It introduces a novel negative damping regime in bilayer graphene systems driven by DC current, linking wave instabilities to moving media phenomena.

Findings

Demonstrates negative Landau damping in bilayer graphene

Predicts spontaneous light emission (spasing) due to drift currents

Highlights potential applications in nanophotonic on-chip light sources

Abstract

We theoretically demonstrate that a system formed by two coupled graphene sheets enables a negative damping regime wherein graphene plasmons are pumped by a DC current. This effect is triggered by electrons drifting through one of the graphene sheets and leads to the spontaneous light emission (spasing) and wave instabilities in the mid-infrared range. It is shown that there is a deep link between the drift-induced instabilities and wave instabilities in moving media, as both result from the hybridization of oscillators with oppositely signed frequencies. With a thickness of few nanometers and wide spectral tunability, the proposed structure may find interesting applications in nanophotonic circuitry as an on-chip light source.