Strong field atomic ionization: Origin of high-energy structures in photoelectron spectra

The time-dependent Schrödinger equation (TDSE) was solved for two different model potentials: one is long range, supporting an infinite number of states, and the other is short range, with no excited state. Simulations for a long-range potential validated the mechanism resulting from a resonant process involving Rydberg states in atoms. On the other hand, simulations performed for short-range potentials emphasized the key role played by laser-induced states (LIS).