Strong Field Ionization Probing of the Transition from a Molecule to Atoms

ORAL

Abstract

We use strong-field ionization to probe electron orbital rearrangement in a dissociating molecule. By illuminating a bromine molecule with 400~nm light, the molecule is excited into a dissociative state. A strong 800 nm pulse is then used to directly probe the dissociative state by ionizing the molecule at different times during the breakup process. We observe time-dependent changes in the kinetic energy release spectra and the angular-dependent ionization yield as the molecular bond ruptures, which we attribute to electronic rearrangement within the molecule. Different orbitals are found to respond differently to the nuclear motion. These data are compared with theoretical predictions, which allow us to identify a well-defined transition from the molecular state into separated atoms for the first time, which occurs at the surprisingly long timescale of 140~fs and an internuclear separation of 5.6 {\AA}.

*Acknowledgment: We would like to thank ARO, DOE and Wayne State University Start-up for funding this project.

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Authors

  • Wen Li

    • Dept. of Chemistry, Wayne State University and JILA and Dept. of Physics, University of Colorado

  • Agnieszka Jaron-Becker

    • JILA and Dept. of Physics, University of Colorado

  • Craig Hogle

    • JILA and Dept. of Physics, University of Colorado

  • Vandana Sharma

    • JILA and Dept. of Physics, University of Colorado

  • Xibin Zhou

    • JILA and Dept. of Physics, University of Colorado

  • Andreas Becker

    • JILA and Dept. of Physics, University of Colorado

  • Henry Kapteyn

    • JILA and Dept. of Physics, University of Colorado

  • Margaret Murnane

    • JILA and Departments of Physics and ECE, University of Colorado at Boulder
    • University of Colorado, JILA
    • JILA and Dept. of Physics, University of Colorado