Macroscopic effects on high-order harmonic generation in disordered semiconductors

We adopt a multi-scale approach to study macroscopic effects on the high-order harmonic generation (HHG) in disordered semiconductors. The propagation of the electromagnetic field is obtained by solving macroscopic Maxwell equations, while the corresponding response of the semiconductor to the electromagnetic field is simulated by solving the microscopic one-particle density matrix equation in the two-band approximation. We compare the results obtained for perfect and disordered crystals. It is found that for the solid HHG radiation to possess spectral features that are consistent with experimental findings, it is important to properly include the effects of both crystal disorder, to a greater extent, and the macroscopic propagation of the electromagnetic field, to a lesser extent, in the theoretical simulations of the corresponding solid HHG experiments.