Dissociation of doubly excited states of H2 into Rydberg atoms

Oxidation of Ultrathin SiGe Layer on Si(001): Evidence for Inward Movement of Ge

“…The accessible Q 1 states therefore encompass those states which can be excited from X 1 + g (v = 0) by one-photon absorption, but with the important difference that the range of internuclear separations where excitation proceeds is shifted to much larger values and the total energy in the molecule is smaller. Figure 1 shows that the Franck-Condon principle allows excitation to all members of the Q 1 manifold with probably only few exceptions where the Franck-Condon overlap integral vanishes accidentally (Verschuur et al 1988). For two-photon transitions from B 1 + u (v = 5, J = 0) to the lowest J = 0 1 + u and 1 u states, the Franck-Condon factors can be calculated using the potential energy curves of Guberman (1983); they are given in the first row of table 1.…”

“…and Cornaggia et al (1986) employed EF 1 + g four-photon resonant rovibrational states to excite to a similar total energy after absorption of two further photons. Verschuur et al (1988) excited the H 2 molecule by three-photon resonant five-photon absorption via single B 1 + u rovibrational levels. These experiments look into the role doubly excited states play in photoionization of H 2 with bound H + 2 vibrational states as final product states and into neutral dissociation induced by the doubly excited states.…”

“…The two horizontal lines indicate the energy in the molecule after absorption of one and two photons, respectively, from B(v = 5). Verschuur et al 1988) or H * * 2 autoionization creating H + 2 ions bound in the electronic ground state 1sσ g (see, for example, Hickman 1987, Verschuur et al 1988, Xu et al 1989. For onephoton excitation from X 1 + g (v = 0) at photon energies in the range 18.08-25.5 eV only direct dissociative photoionization (process (1)) is possible with excitation to the dissociation continuum of the H + 2 ground electronic state 1sσ g (Ito et al 1996) (see figure 1).…”

“…Thus specific initial conditions for the following decay are created. Like Verschuur et al (1988) we modify these initial conditions by using single B 1 + u (v = 5) rotational levels as initial states for excitation. Starting at v = 5 we excite by absorption of two photons withhω ≈ 4 eV energy.…”

The line profiles of single rotational lines of the H 2 B - X(3, 0) band in an intense infrared light field

“…With few exceptions the first excitation scheme is used to study resonant phenomena at light intensities limited to less than ≈ 10 12 W/cm 2 [7][8][9][10][11][12]. In the second scheme excitation is usually "nonresonant" at least as long as the AC-Stark shift of molecular states does not give rise to transient resonances at specific light intensities.…”