Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules

Journal Article · Fri Jul 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.013429· OSTI ID:22051340

Shaaran, T; Augstein, B B

We address the influence of the molecular orbital geometry and of the molecular alignment with respect to the laser-field polarization on laser-induced nonsequential double ionization of diatomic molecules for different molecular species, namely N{sub 2} and Li{sub 2}. We focus on the recollision excitation with subsequent tunneling ionization (RESI) mechanism, in which the first electron, upon return, promotes the second electron to an excited state, from where it subsequently tunnels. We assume that both electrons are initially in the highest occupied molecular orbital (HOMO) and that the second electron is excited to the lowest unoccupied molecular orbital (LUMO). We show that the electron-momentum distributions exhibit interference maxima and minima due to the electron emission at spatially separated centers. We provide generalized analytical expressions for such maxima or minima, which take into account s-p mixing and the orbital geometry. The patterns caused by the two-center interference are sharpest for vanishing alignment angle and get washed out as this parameter increases. Apart from that, there exist features due to the geometry of the LUMO, which may be observed for a wide range of alignment angles. Such features manifest themselves as the suppression of probability density in specific momentum regions due to the shape of the LUMO wave function, or as an overall decrease in the RESI yield due to the presence of nodal planes.

• OSTI ID: 22051340
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ELECTRON EMISSION
ELECTRONS
EXCITATION
EXCITED STATES
GEOMETRY
INTERFERENCE
IONIZATION
LASER RADIATION
LITHIUM SULFIDES
MOLECULAR ORBITAL METHOD
MOLECULES
POLARIZATION
TUNNEL EFFECT
WAVE FUNCTIONS