Abstract
The strong-field many-electron dynamics is studied via the resonance-enhanced high-order harmonic generation (HHG) of niobium. In intense IR lights excited states of Nb with the configuration play a vital role in the enhanced HHG below the ionization potential, even though the electron initially occupying the orbital is the most active. The energies of these states increase linearly with the laser intensity, which causes the effective ionization potential to increase as well. Above the ionization potential, many-electron effects may cause an electronic state of Nb to be in resonance with that of , which leads to enhanced HHG and which influences the tunneling ionization as well.
- Received 21 January 2022
- Revised 9 April 2022
- Accepted 26 April 2022
DOI:https://doi.org/10.1103/PhysRevA.105.053110
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