Attosecond strobing of two-surface population dynamics in dissociating H\u2082+

Using H2+ and D2+, we observe two-surface population dynamics by measuring the kinetic energy of the correlated ions that are created when H2+ (D2+) ionize in short (40-140 fs) and intense (1014W/cm2) infrared laser pulses. Experimentally, we find a modulation of the kinetic energy spectrum of the correlated fragments. The spectral progression arises from a hitherto unexpected spatial modulation on the excited state population, revealed by Coulomb explosion. By solving the two-level time-dependent Schr\uf6dinger equation, we show that an interference between the net-two-photon and the one-photon transition creates localized electrons which subsequently ionize. \ua9 2007 The American Physical Society.Peer reviewed: YesNRC publication: Ye