Physical Review A
Atomic ionization driven by the quantized electromagnetic field in a Fock state
Igor A. Ivanov, Kyung Taec Kim
Abstract
We consider ionization of an atom by the electromagnetic field in a Fock state $|N\ensuremath{\rangle}$: An eigenvector of the operator ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{N}}_{\mathbit{k},\ensuremath{\lambda}}={\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}_{\mathbit{k},\ensuremath{\lambda}}^{\ifmmode\dagger\else\textdagger\fi{}}{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}_{\mathbit{k},\ensuremath{\lambda}}$ of the number of photons in the mode $\mathbit{k},\ensuremath{\lambda}$. We treat the electromagnetic field in a quantized way, which allows us to obtain the photon picture of the strong field ionization. We obtain, in particular, probability distributions for the number of absorbed photons in the process of strong field ionization for atomic systems governed by short-range and Coulomb potentials.