Ionization of excited H atoms by a bichromatic field

Magda Fifirig, Aurelia Cionga

Constantine Mavroyannis

Kazuki Komatsu, A. Takamine, Yoshihiro MIZUGAI +1 more

We report theoretical study on ionization suppression of Rydberg atom by bichromatic microwave field.In the framework of one-dimensional classical model we find that with the monochromatic microwave field of (angular) frequency 2 and amplitude 2F one-dimensional Rydberg atom is ionized, while adding the second microwave field of frequency  and amplitude F to the atom subjected to the first microwave field prohibits ionization of the Rydberg atom in case Kepler frequency of the Rydberg atom excited in the state of principal quantum number n, 1/n 3 , nearly matches K/4( +2) with K = 1.

Daniel I. Khomskii

Грызлова Елена Владимировна, Alexei N. Grum-Grzhimailo, Ekaterina I. Staroselskaya +2 more

We investigate the coherent control of the photoelectron angular distribution in bichromatic atomic ionization. Neon is selected as target since it is one of the most popular systems in current gas-phase experiments with free-electron lasers (FELSs). In particular, we tackle practical questions, such as the role of the fine-structure splitting, the pulse length, and the intensity. Time-dependent and stationary perturbation theory are employed, and we also solve the time-dependent Schr\"odinger equation in a single-active electron model. We consider neon ionized by a FEL pulse whose fundamental frequency is in resonance with either $2p\text{\ensuremath{-}}3s$ or $2p\text{\ensuremath{-}}4s$ excitation. The contribution of the nonresonant two-photon process and its potential constructive or destructive role for quantum coherent control is investigated.

Fred L. Mohler