High-Harmonic Generation from Monolayer and Bilayer Graphene

TL;DR

This paper investigates high-harmonic generation in monolayer and bilayer graphene, revealing how stacking and interlayer coupling influence harmonic spectra and polarization properties at ultrafast timescales.

Contribution

It provides a comparative analysis of HHG in monolayer and bilayer graphene, highlighting the effects of stacking and interlayer interactions on harmonic spectra.

Findings

Monolayer and bilayer graphene exhibit distinct harmonic spectra.

Interlayer coupling significantly affects the harmonic generation.

Polarization and ellipticity dependence vary between monolayer and bilayer graphene.

Abstract

High-harmonic generation (HHG) in solids is an emerging method to probe ultrafast electron dynamics in solids at attosecond timescale. In this work, we study HHG from monolayer and bilayer graphene. Bilayer graphenes with AA and AB stacking are considered in this work. It is found that the monolayer and bilayer graphenes exhibit significantly different harmonic spectra. The difference in the spectra is attributed to the interlayer coupling between the two layers. Also, the intraband and interband contributions to the total harmonic spectrum play a significant role. Moreover, interesting polarization and ellipticity dependence are noticed in total harmonic spectrum for monolayer and bilayer graphene.