Abstract
High-order harmonic generation (HHG) has unleashed the power of strong laser physics in solids. Here we investigate HHG from a large system, solid , with 240 valence electrons engaging harmonic generation at each crystal momentum. We employ the density functional theory and the time-dependent Liouville equation of the density matrix to compute HHG signals. We find that under a moderately strong laser pulse, HHG signals reach 15th order, consistent with the experimental results from plasma. The helicity dependence in solid is weak, due to the high symmetry. In contrast to the general belief, HHG is unsuitable for band structure mapping in . However, we find a window of opportunity using a long wavelength, where harmonics are generated through multiple-photon excitation. In particular, the fifth-order harmonic energies closely follow the transition energy dispersion between the valence and conduction bands. This finding is expected to motivate future experimental investigations.
- Received 6 January 2020
- Accepted 14 February 2020
DOI:https://doi.org/10.1103/PhysRevB.101.081412
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