Wave mixing and high harmonic generation at two-color multiphoton excitation in two-dimensional hexagonal nanostructures

Abstract

The high-order wave mixing by two-color multiphoton excitation in nonlinear regime along with the harmonics generation in two-dimensional (2D) nanostructures such as graphene, silicene, germanene, and stanene is investigated. We consider the coherent part of the spectra corresponding to high harmonic generation by two-color intense laser pulses. The developed theory of interaction of free carriers with the driving effective field of two-color waves covers the full Brillouin zone of 2D hexagonal nanostructures. We also consider the case when one of the driving waves is in one-photon resonance with the van Hove singularity at the $M$ point of the Brillouin zone. Obtained results show that novel 2D nanostructures can serve as an effective medium for high-order wave mixing and harmonic generation at the two-color multiphoton excitation with strong laser pulses.