LETTER TO THE EDITOR Suppression of electron correlation and of autoionization by strong laser fields

Abstract. General considerations and explicit computations using highly correlated Hylleraas-type wavefunctions demonstrate how doubly electronically excited autoionizing helium can be stabilized in the presence of a KrF laser at laboratory field intensities. This type of stabilization is due to the abrupt suppression of the dynamical electronic correlation as the field intensity is increased beyond a critical value. The generality of the result is stressed. Recently, there has been an increasing experimental and theoretical effort to investigate the photo-induced dynamics in strong laser fields. One of the new physical phenomena which attracted a great deal of attention from the researchers in the field is the stabilization of atoms in high-intensity fields. It has been shown that in strong high-frequency fields where perturbation theory breaks down, the increase of the field beyond a critical value leads to a reduction of the ionization rate of atoms initially found in their ground state [1–3]. The prolongation of the lifetime of the neutral atom in a sufficiently strong AC field should affect the corresponding above-threshold ionization (ATI) spectra. It is expected that narrowing of the ATI peaks will be observed as the field is increased beyond a critical value [4, 5]. In the high laser frequency!L regime the lifetimes of ground and singly excited electroni