Filming enhanced ionization in an ultrafast triatomic slingshot.

Filming atomic motion within molecules is an active pursuit of molecular physics and quantum chemistry. A promising method is laser-induced Coulomb Explosion Imaging (CEI) where a laser pulse rapidly ionizes many electrons from a molecule, causing the remaining ions to undergo Coulomb repulsion. The ion momenta are used to reconstruct the molecular geometry which is tracked over time (i.

Strictly non-adiabatic quantum control of the acetylene dication using an infrared field.

We demonstrate the existence of a strictly non-adiabatic control pathway in deprotonation of the acetylene dication. This pathway is identified experimentally by measuring a kinetic energy shift in an ion coincidence experiment. We use a time dependent Schrödinger equation simulation to identify which properties most strongly affect our control.

Ionization induced dynamic alignment of water.

Two-body dissociation resulting from strong-field double ionization of water is investigated. Two distinct features are seen in the alignment of the fragment momenta with respect to the laser polarization. One feature shows alignment of the H-OH axis with the laser polarization, while the other indicates polarization alignment normal to the H-OH axis.

Geometric dependence of strong field enhanced ionization in DO.

We have studied strong-field enhanced dissociative ionization of DO in 40 fs, 800 nm laser pulses with focused intensities of <1-3 × 10W/cm by resolving the charged fragment momenta with respect to the laser polarization. We that observe dication dissociation into OD/D dominates when the polarization is out of the plane of the molecule, whereas trication dissociation into O/D/D is strongly dominant when the polarization is aligned along the D-D axis. Dication dissociation into O/D/D and O/D is not seen nor is there any significant fragmentation into multiple ions when the laser is polarized along the C symmetry axis of the molecule.

Coherent control using kinetic energy and the geometric phase of a conical intersection.

Conical intersections (CIs) between molecular potential energy surfaces with non-vanishing non-adiabatic couplings generally occur in any molecule consisting of at least three atoms. They play a fundamental role in describing the molecular dynamics beyond the Born-Oppenheimer approximation and have been used to understand a large variety of effects, from photofragmentation and isomerization to more exotic applications such as exciton fission in semiconductors. However, few studies have used the features of a CI as a tool for coherent control.