Two-center interferences in photoionization of a dissociating H{sub 2}{sup +} molecule

Journal Article · Sat Jan 15 04:00:00 EST 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.013414· OSTI ID:21537009

Picon, A; Kapteyn, H C; Murnane, M M; Becker, A ^[1]; Bahabad, A ^[1]

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1. JILA and Department of Physics, University of Colorado at Boulder, Boulder, Colorado 80309-0440 (United States)

We analyze two-center interference effects in the yields of ionization of a dissociating hydrogen molecular ion by an ultrashort vuv laser pulse. To this end, we performed numerical simulations of the time-dependent Schroedinger equation for a H{sub 2}{sup +} model ion interacting with two time-delayed laser pulses. The scenario considered corresponds to a pump-probe scheme, in which the first (pump) pulse excites the molecular ion to the first excited dissociative state and the second (probe) pulse ionizes the electron as the ion dissociates. The results of our numerical simulations for the ionization yield as a function of the time delay between the two pulses exhibit characteristic oscillations due to interferences between the partial electron waves emerging from the two protons in the dissociating hydrogen molecular ion. We show that the photon energy of the pump pulse should be in resonance with the {sigma}{sub g}-{sigma}{sub u} transition and the pump pulse duration should not exceed 5 fs in order to generate a well-confined nuclear wave packet. The spreading of the nuclear wave packet during the dissociation is found to cause a decrease of the amplitudes of the oscillations as the time delay increases. We develop an analytical model to fit the oscillations and show how dynamic information about the nuclear wave packet, namely, velocity, mean internuclear distance, and spreading, can be retrieved from the oscillations. The predictions of the analytical model are tested well against the results of our numerical simulations.

• OSTI ID: 21537009
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BARYONS
BOSONS
CATIONS
CHARGED PARTICLES
COMPUTERIZED SIMULATION
DIFFERENTIAL EQUATIONS
DISSOCIATION
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EQUATIONS
FAR ULTRAVIOLET RADIATION
FERMIONS
HADRONS
HYDROGEN
HYDROGEN IONS
HYDROGEN IONS 2 PLUS
IONIZATION
IONS
LEPTONS
MASSLESS PARTICLES
MOLECULAR IONS
NONMETALS
NUCLEONS
OPTICAL PUMPING
OSCILLATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PHOTOIONIZATION
PHOTONS
PROTONS
PULSES
PUMPING
RADIATIONS
RESONANCE
SCHROEDINGER EQUATION
SIMULATION
TIME DELAY
TIME DEPENDENCE
ULTRAVIOLET RADIATION
WAVE EQUATIONS
WAVE PACKETS