Nonlinear electromagnetic response of few-layer graphene: A nonperturbative description

D. V. Fil

Published 2020-01-23Version 1

Nonperturbative approach based on exact solution of Boltzmann kinetic equation in the relaxation time approximation is developed for the study of nonlinear response of electron-doped few-layer graphene to a high-frequency electromagnetic field. It is shown that nonperturbative approach can be applied to a two-dimensional conductor with an arbitrary isotropic spectrum of carries. The cases of ABC stacked three-layer and ABC staked four-layer graphene are considered. The transmission, reflection and absorption coefficients are calculated. It is found that three-layer and four-layer graphenes demonstrate power-induced reflectance, in contrast to power-induced transparency in monolayer graphene. The analytical expression for the efficiency of the third-harmonic generation (THG), the ratio of the intensity of third-harmonic radiation to the intensity of the incident wave of the four-layer graphene is obtained. It is shown that only at rather small incident wave intensity the THG efficiency is proportional to the second power of input intensity and at large incident wave intensity the THG efficiency approaches the constant quantity. Saturation of the THG efficiency is caused by the increase of the reflection. In contrast, the THG efficiency in monolayer graphene depends nonmonotonically on the intensity of the incident wave. The THG efficiency in monolayer graphene is two orders of magnitude smaller than in four-layer graphene.