par Joachain, Charles 
;Kylstra, Niels Jan
Référence Physical Review A, 100, 1, 013417
Publication Publié, 2019-07
;Kylstra, Niels Jan Référence Physical Review A, 100, 1, 013417
Publication Publié, 2019-07
Article révisé par les pairs
| Résumé : | The direct multiphoton ionization (MPI) of hydrogenlike ions by intense, linearly polarized, ultrashort infrared laser pulses is investigated within the framework of the strong field approximation (SFA) for laser peak intensities and angular frequencies where relativistic effects are important. We obtain an expression for the differential MPI probability using the Dirac equation and demonstrate that, for the particular case of light ions, the Dirac spin-unresolved MPI probabilities agree with those obtained using the Klein-Gordon equation as well as the relativistic Schrödinger equation. As an example, the interaction of hydrogenlike neon ions with an intense four-cycle Ti:sapphire laser pulse is considered. We show that, in contrast to the nonrelativistic regime, for ultrashort pulses in the relativistic regime, interference effects do not play a role in determining the main features of the energy-resolved photoelectron spectrum. Moreover, we find that the angle-integrated photoelectron spectrum can be obtained using the well-known nonrelativistic SFA formula, properly adjusted to account for the electron drift along the laser propagation direction. |
