High-harmonic generation from 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 a monolayer and bilayer graphene, exposed by an intense mid-infrared laser pulse. Bilayer graphene with AA and AB stacking are considered in this work. It is found that the monolayer and bilayer graphene exhibit significantly different harmonic spectra. The difference in the spectra is attributed to the interlayer coupling between the two layers. Pronounced interplay of intraband and interband contributions to the harmonic spectrum is found. Moreover, peculiar polarisation and ellipticity dependence are noticed in monolayer and bilayer graphene.