Relativistic effects in the multiphoton ionization of hydrogenlike ions by ultrashort infrared laser pulses

Abstract

The ionization of hydrogenlike ions in short few-cycle laser pulses of high intensity is investigated using the strong-field approximation. It is found that, for light ions, the Klein-Gordon or a relativistic Schr\odinger treatment agrees well with the results from a full Dirac description when an average over the electron spin is taken.