title: Attosecond control in photoionization of hydrogen molecules.
abstract: We report experiments where hydrogen molecules were dissociatively ionized by an attosecond pulse train in the presence of a near-infrared field. Fragment ion yields from distinguishable ionization channels oscillate with a period that is half the optical cycle of the IR field. For molecules aligned parallel to the laser polarization axis, the oscillations are reproduced in two-electron quantum simulations, and can be explained in terms of an interference between ionization pathways that involve different harmonic orders and a laser-induced coupling between the 1sσ(g) and 2pσ(u) states of the molecular ion. This leads to a situation where the ionization probability is sensitive to the instantaneous polarization of the molecule by the IR electric field and demonstrates that we have probed the IR-induced electron dynamics with attosecond pulses.
authors.affiliation: FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Kelkensberg
authors.forename: W
authors.initials: W
authors.lastname: Siu
authors.forename: J F
authors.initials: JF
authors.lastname: Pérez-Torres
authors.forename: F
authors.initials: F
authors.lastname: Morales
authors.forename: G
authors.initials: G
authors.lastname: Gademann
authors.forename: A
authors.initials: A
authors.lastname: Rouzée
authors.forename: P
authors.initials: P
authors.lastname: Johnsson
authors.forename: M
authors.initials: M
authors.lastname: Lucchini
authors.forename: F
authors.initials: F
authors.lastname: Calegari
authors.forename: J L
authors.initials: JL
authors.lastname: Sanz-Vicario
authors.forename: F
authors.initials: F
authors.lastname: Martín
authors.forename: M J J
authors.initials: MJ
authors.lastname: Vrakking