TY - JOUR
AU - Daniel Slaughter
AU - F. Sturm
AU - Roger Bello
AU - K.A. Larsen
AU - N. Shivaram
AU - C. McCurdy
AU - Robert Lucchese
AU - L. Martin
AU - C.W. Hogle
AU - Margaret Murnane
AU - Henry Kapteyn
AU - Predrag Ranitovic
AU - Thorsten Weber
AB - D2 molecules, excited by linearly cross-polarized femtosecond extreme ultraviolet (XUV) and near-infrared (NIR) light pulses, reveal highly structured D+ ion fragment momenta and angular distributions that originate from two different 4-step dissociative ionization pathways after four photon absorption (1 XUV + 3 NIR). We show that, even for very low dissociation kinetic energy release ≤~240~meV, specific electronic excitation pathways can be identified and isolated in the final ion momentum distributions. With the aid of {\it ab initio} electronic structure and time-dependent Schrödinger equation calculations, angular momentum, energy, and parity conservation are used to identify the excited neutral molecular states and molecular orientations relative to the polarization vectors in these different photoexcitation and dissociation sequences of the neutral D2 molecule and its D+2 cation. In one sequential photodissociation pathway, molecules aligned along either of the two light polarization vectors are excluded, while another pathway selects molecules aligned parallel to the light propagation direction. The evolution of the nuclear wave packet on the intermediate \Bstate electronic state of the neutral D2 molecule is also probed in real time.
BT - Physical Review Research
DA - 2021-08
DO - 10.1103/PhysRevResearch.3.033191
N2 - D2 molecules, excited by linearly cross-polarized femtosecond extreme ultraviolet (XUV) and near-infrared (NIR) light pulses, reveal highly structured D+ ion fragment momenta and angular distributions that originate from two different 4-step dissociative ionization pathways after four photon absorption (1 XUV + 3 NIR). We show that, even for very low dissociation kinetic energy release ≤~240~meV, specific electronic excitation pathways can be identified and isolated in the final ion momentum distributions. With the aid of {\it ab initio} electronic structure and time-dependent Schrödinger equation calculations, angular momentum, energy, and parity conservation are used to identify the excited neutral molecular states and molecular orientations relative to the polarization vectors in these different photoexcitation and dissociation sequences of the neutral D2 molecule and its D+2 cation. In one sequential photodissociation pathway, molecules aligned along either of the two light polarization vectors are excluded, while another pathway selects molecules aligned parallel to the light propagation direction. The evolution of the nuclear wave packet on the intermediate \Bstate electronic state of the neutral D2 molecule is also probed in real time.
PY - 2021
EP - 033191
T2 - Physical Review Research
TI - Nonequilibrium dissociative dynamics of D2 in two-color, few-photon excitation and ionization
UR - https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.3.033191
VL - 3
ER -