Ionization of a model quantum system by a single mode electromagnetic cavity field

Abstract

Abstract:The ionization of a model atom in a strong singlemode non-classical electromagnetic field is studied beyond the perturbation approach using the model of "one discrete level + continuum" for the atom. Explicit analytical expressions for the time-dependent probability of atomic ionization are obtained for different initial states of radiative field: Fock state, coherent wave packet, squeezed vacuum state. The results are compared to the ionization decay of discrete atomic level in a classical light field, and are analyzed for different mean number of radiative photons. The time-dependent distribution of the quantized field over photon number states is examined. The time-dependent bound atomic probability calculated in the case of different initial field states (Fock, coherent, and squeezed vacuum states). The mean number of photons is equal to unity

Phase-sensitive excitation of atomic systems and semiconductor quantum wells by non-classical light

“…It is seen that for ∆ + θ = π when condition ( 23) is fulfilled, the Schmidt parameter is equal to 1 that means a pure state for the atom and its total disentanglement from quantum fields. In contrast, for the total phase ∆ + θ = π 2 the entanglement is found to be the largest one since all of the quasienergy states (19) and (20) are populated. Though in this case the Schmidt parameter does not reach its maximal value, it can be further enlarged by changing the initial mean photon numbers of quantum fields and strength of their interaction with atom.…”

“…For correct description of coherent state we should take into account Fock states with numbers in few standard deviations around N . As for the squeezed vacuum state, it is characterized by much more broader distribution over Fock states with only even numbers contributing to field wave function [20]:…”

Phase dependence in the ionization of atoms by intense one-cycle laser pulses within the Landau–Dykhne approximation

“…This problem was discussed in detail in [28] within the strong-field approximation for irradiation by a few-cycle laser pulse. Unlike the ionization probabilities, the difference between cosine and sine waveforms takes place also for 3-4 cycle laser pulses [29,30]. The above Landau-Dykhne approach allows us to obtain analytic expressions for the energy spectra.…”

Relativistic effects in the many-body theory of extreme multiplicity ion formation in superstrong laser fields

“…Classical and semi-classical methods [20][21][22] are based on ideas of the photoelectron motion along the classical trajectories. Numerical methods, as a rule, are based on the Hartree-Fock approximation [23][24][25][26], the quasi-energies method [27] or the Kramers method [28][29][30][31].…”