Phase-dependent atomic ionization in few-cycle intense laser fields

We have studied the carrier-envelope phase-dependent above-threshold-ionization processes by solving the time-dependent Schr\"odinger equation nonperturbatively. Our simulated carrier-envelope phase-dependent above-threshold-ionization spectra are in good agreement with the experimental measurement of Paulus et al. [Phys. Rev. Lett. 91, 253004 (2003)] if we shift the experimental carrier-envelope phase by 0.15π. This means that we have recalibrated the carrier-envelope phase more accurately by comparing our simulations with the experimental measurements. Furthermore, by tracing back the origin of the ionized electrons, we have clearly identified that the low-energy electrons come from the direct ionization by the laser field and the high-energy electrons come from the recollision with the parent core after being bounced back by the laser field.