Laser-field-strength dependence of solid high-order harmonic generation from doped systems

We have theoretically studied the field-strength-dependent high-order harmonic generation (HHG) from doped systems like nanosize or bulk materials. Our results show that when the amplitude of the vector potential Apeak of the driving laser reaches the half-width of the Brillouin zone (& pi;/a0), the harmonic yield of the undoped systems is larger than that of the doped systems. The band-climbing process enhances the interband transition of HHG for higher conduction bands. We find that the donor-doped states and valence-band states from the doped system both contribute to the HHG. The destructive interference between the above two channels results in the harmonic yield from the undoped system overtaking that of the doped system when Apeak is around or higher than & pi;/a0, especially when the phase of HHG contributed by the above two channels is close to & pi; rad. When Apeak is below & pi; /a0, the harmonic yield of the doped systems is stronger than that of the undoped systems. The atomic doping density also influences the field-strength-dependent spectra.

Automated summary

We have investigated the effect of field strength on high-order harmonic generation (HHG) in doped systems such as nanosize or bulk materials. Our findings reveal that when the amplitude of the driving laser's vector potential reaches the half-width of the Brillouin zone, the harmonic yield of undoped systems surpasses that of doped systems. This is due to the band-climbing process, which enhances the interband transition of HHG for higher conduction bands. Additionally, the interference between donor-doped states and valence-band states contributes to the HHG.