Classical support for non-dispersive two-electron wave packets in the driven helium atom

Abstract

We present numerical evidence for the existence of a classically non-ionizing, highly correlated two-electron configuration which emerges from the frozen planet configuration of helium exposed to an electromagnetic field of linear polarization. A static electric field parallel to the polarization axis prevents this configuration from transverse ionization. We argue that the corresponding nonlinear resonance island in 12D phase space supports nondispersive wave packets of the helium atom in combined oscillating and static electric fields.