Routes to formation of highly excited neutral atoms in the breakup of strongly driven H2

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1103/PhysRevA.85.011402Physical Review, 85, 1, pp. 011402-1-011402-4, 2012-01-11 Routes to formation of highly excited neutral atoms in the breakup of strongly driven H2 Emmanouilidou, A.; Lazarou, C.; Staudte, A.; Eichmann, U. We present a theoretical quasiclassical treatment of the formation, during Coulomb explosion, of highly excited neutral H atoms (H * ) for strongly driven H 2 . This process, where after the laser field is turned off, one electron escapes to the continuum while the other occupies a Rydberg state, was recently reported in an experimental study [B. Manschwetus et al., Phys.Rev .Lett.102, 113002 (2009)]. We find that two-electron effects are important in order to correctly account for all pathways leading to H * formation. We identify two pathways where the electron that escapes to the continuum does so either very quickly or after remaining bound for a few periods of the laser field. These two pathways of H * formation have distinct traces in the probability distribution of the escaping electron momentum components.

Toolkit for semiclassical computations for strongly driven molecules: Frustrated ionization ofH2driven by elliptical laser fields

“…We present the technique in the context of N Coulomb interacting particles that are driven by a laser field. Previously, in [15,18], we formulated the equations of motion using the global regularization scheme described in [19]. In this latter work, the resulting equations of motion were propagated using the 5th order Runge-Kutta method [21].…”

“…Combining these two techniques has been used successfully to describe gravitational fewbody systems [20,23,24]. The advantage of the current propagation technique over the one we previously used in [15,18] is that it is numerically more robust with a smaller propagation error. One reason is that, unlike the technique we previously used, in the current technique the masses do not enter in the time-transformation resulting in a more accurate treatment of many-body systems with large mass ratios [20].…”

“…One reason is that, unlike the technique we previously used, in the current technique the masses do not enter in the time-transformation resulting in a more accurate treatment of many-body systems with large mass ratios [20]. Note that the current technique as well as the technique we previously used in [15,18] explicitly account for the accurate treatment of the Coulomb singularity during time propagation. This is an essential ingredient of an accurate classical treatment, since classically an electron is allowed to come infinitely close to a nucleus.…”

“…(19) is singular. Previously, in [15,18], this issue was addressed by transforming to regularized coordinates [19]. In the current work, to address the singularity, we use the time-transformed leapfrog method that is described in [20]; we can do so, since in Eq.…”

“…In [15] we reported a theoretical study of the mechanisms of this "frustrated"-since only one electron eventually escapes-double ionization process. The break-up of H 2 into a proton, a Rydberg atom (H * ) and an escaping electron through Coulomb explosion of the nuclei is a significant phenomenon.…”