Nonsequential double ionization: Recent insights
It is well established that laser induced correlated electron emission at intermediate intensities and near-infrared wavelengths proceeds via the rescattering mechanism. According to this picture, one electron, excited to the continuum by the field, is accelerated and driven back to the parent ion by the oscillating field where it can supply energy to liberate a second or even more electrons. This seemingly well understood process however still bare new facets.
In a joint experimental-theoretical work a fingerlike structure in the correlated
electron momentum distributions following double ionization of helium has been observed.
Results of numerical simulations show that this feature is a signature of the microscopic
dynamics in the recollision process. It is interpreted to result from electron-impact ionization with
backscattering of the electron at the nucleus upon recollision.
A. Staudte et al., Phys. Rev. Lett. 99 (2007) 263002
Collaboration: P. Corkum (NRC Ottawa, Canada); R. Dörner (University
Frankfurt, Germany)
Results of computations of correlated electron dynamics in the hydrogen molecule using
a model of planar molecules with static nuclei have indicated two
new pathways to nonsequential double ionization, namely (a) the decay
of double excited states, created during the recollision event (a snapshot
of the process has
been selected for the Kaleidoscope section of Phys. Rev. A), and (b)
correlated electron emission after soft recollision.
S. Baier et al., Phys. Rev. A 78 (2008) 013409
Collaboration: L. Plaja (Universidad Salamanca, Spain)
