High-order harmonic generation in semiconductors driven at near- and mid-infrared wavelengths

We study high-order harmonics generation (HHG) in crystalline silicon and diamond subjected to near- and mid-infrared laser pulses. We employ time-dependent density functional theory and solve the time-dependent Kohn-Sham equation in the single-cell geometry. We demonstrate that clear and clean HHG spectra can be generated with careful selection of the pulse duration. In addition, we simulate dephasing effects in a large silicon supercell through a displacement of atomic positions prepared by a molecular dynamics simulation. We compare our results with the previous calculations by Floss et al. [Phys. Rev. A 97, 011401(R) (2018)10.1103/PhysRevA.97.011401] on diamond at 800 nm and by Tancogne-Dejean et al. [Phys. Rev. Lett. 118, 087403 (2017)10.1103/PhysRevLett.118.087403] on Si at 3000 nm.