Photoelectron asymmetries and puzzling molecular dynamics in the two-color dissociative photoionization of molecular hydrogen by synchrotron extreme ultraviolet and near infrared laser pulses. 

POSTER

Abstract

The coupled electronic and nuclear dynamics in the dissociation of the simplest molecular ion, H2+ are investigated by electron-ion coincidence momentum imaging experiments employing synchrotron extreme ultraviolet (SXUV) and delayed near infrared (NIR) laser pulses of moderate intensity (peak intensity I ≈ 1011 W/cm2). Using first principles time-dependent theory we show that the SXUV photoionization populates vibrationally excited H2+ (X 2Σg+, ν=6 to ν=15), and we find evidence for asymmetry imprinted in the molecular frame of H2+ by the NIR laser pulses due to charge-resonance enhanced dissociation. The experimental and computational results illuminate the various roles of charge resonance enhanced dissociation, bond-softening and light-induced conical intersections. The molecular frame photoelectron angular distributions (MFPADs) exhibit asymmetries that depend on the H2+ vibrational level and the SXUV-NIR delays, revealing the mechanisms by which the NIR field couples the bound and dissociative nuclear wavefunctions.

*This research was supported by U.S Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract Nos. DE-AC02-05CH11231, DE-FG02-86ER13491, and DE-SC0017984. This research used resources of the Advanced Light Source (ALS) and the National Energy Research Scientific Computing Center (NERSC), both being DOE Office of Science User Facilities under contract no. DE-AC02-05CH11231. In particular we acknowledge NERSC award BES-ERCAP-0031386903 (experiment). We thank the staff of the ALS, in particular beamline 10.0.1 scientist E. A. Fedorov for his outstanding support. We are indebted to the RoentDek Company for long-term support with detector software and hardware.

Presenters

  • Daniel S Slaughter

    • Lawrence Berkeley National Laboratory
    • Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

Authors

  • Daniel S Slaughter

    • Lawrence Berkeley National Laboratory
    • Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

  • Jan Dvorak

    • Lawrence Berkeley National Laboratory

  • Spenser James Burrows

    • Auburn University

  • Averell S Gatton

    • Auburn University

  • Elio G Champenois

    • Lawrence Berkeley National Laboratory

  • Wael Iskandar

    • Lawrence Berkeley National Laboratory

  • Kirk A Larsen

    • Lawrence Berkeley National Laboratory and University of California Berkeley

  • Travis Severt

    • Kansas State University

  • Robert Ross Lucchese

    • Lawrence Berkeley National Laboratory

  • C W McCurdy

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory and University of California Davis
    • University of California, Davis

  • Demitri Call

    • University of Nevada, Reno

  • Vernon Davis

    • University of Nevada, Reno

  • Bethany Christine Jochim

    • Michigan State University

  • Benjamin Berry

    • Kansas State University

  • Daniel Metz

    • Goethe-Universitat Frankfurt

  • Thomas Nicola Rescigno

    • Lawrence Berkeley National Laboratory

  • Hendrik Sann

    • Goethe-Universitat Frankfurt

  • Niranjan Shivaram

    • Purdue University

  • Miriam Weller

    • Goethe-Universitat Frankfurt

  • Itzik Ben-Itzhak

    • J.R. Macdonald Laboratory, Physics, Kansas State University

  • Reinhard Doerner

    • Goethe University Frankfurt

  • Joshua B Williams

    • University of Nevada, Reno

  • Guillaume Marc Laurent

    • Auburn University

  • Thorsten Weber

    • Lawrence Berkeley National Laboratory