Chair: André Staudte, NRC Ottawa, Canada

  • Stefan Pabst
  • Matthias Kübel-Schwarz
  • Johann Förster
  • Igor Litvinyuk
  • Allan Johnson

#82, 12:15 – 12:30 Creating coherent hole wave packets with strong-field pulses, STEFAN PABST AND HANS JAKOB WÖRNER, A new approach is identified that can generate highly coherent hole wave packets with multi-cycle strong-field pulses and stands in contrast to the usual idea of making the ionizing pulse as short as possible. The effect is demonstrated in atomic xenon with a spin-orbit wave packet involving the 5p3/2 -1 and 5p1/2 -1 ionic states.

#83, 12:30 – 12:45 Controlling and Tracing Bond Rearrangements in Hydrocarbons with Few-Cycle Laser Pulses, M. KÜBEL-SCHWARZ, R. SIEMERING, C. BURGER, H. LI, NORA G. KLING, A.S. ALNASER, K.J. BETSCH, J. SCHMIDT, U. KLEINEBERG, I. BEN-ITZHAK, R. MOSHAMMER, R. DE VIVIE-RIEDLE, AND M.F. KLING, In this work, strongfield control of photochemical reactions is combined with Coulomb explosion imaging (CEI) using a reaction microscope. Structural rearrangements in hydrocarbons are induced by phase-controlled few-cycle laser pulses, where the direction of the bound-nuclei motion is steered by the carrier-envelope phase of the driving laser pulse. Quantum mechanical calculations reveal that the laser waveform creates a superposition of vibrational modes that leads to a preferential direction in the hydrogen migration. The temporal evolution of the hydrogen migration is monitored experimentally by CEI in up to four ionic fragments, providing a benchmark for the calculated wavepacket dynamics.

#84, 12:45 – 13:00 Geometry-Dependent Ionization of the Ammonia Molecule and its Application to the Creation and Imaging of Nuclear Wave Packets, JOHANN FÖRSTER AND ALEJANDRO SAENZ, We investigate the ionization behavior of the ammonia molecule as a function of the inversion coordinate (umbrella motion). Different approaches for obtaining the ionization yield are compared, all of them showing a strong dependence of the ionization yield on the inversion coordinate, especially at long wavelengths (above 800 nm). We show how this effect can be exploited to create and probe a nuclear wave packet in neutral ammonia. Furthermore, we propose dedicated experiments to image this motion by measuring the ionization yield or high-harmonic spectra.

#85, 13:00 – 13:15 Effect of Nuclear Mass in Strong-Field Ionization of Hydrogen Molecules and Dissociation of Hydrogen Molecular Ions, IGOR V. LITVINYUK, XIAOSHAN WANG, HAN XU, D. KIELPINSKI, R.T. SANG, We measure isotope effect in strong-field ionization and dissociation of molecular hydrogen using a mixedgas target in a Reaction Microscope (REMI). We compare experimental results with theoretical predictions.

#86, 13:15 – 13:30 High Harmonic Spectroscopy of Substituted Benzenes with a mid-IR source, ALLAN S JOHNSON, FELICITY MCGRATH, MARTA CASTILLEJO, PETER HAWKINS, LUKAS MISEIKIS, THOMAS SIEGEL, EMMA SIMPSON, CHRISTIAN STRÜBER, RICARDO TORRES, DAVID WOOD, DANE R AUSTIN, AND JONATHAN P MARANGOS, We present a comparative study of the high harmonic spectrum of benzene and various substituted benzenes using the idler of an OPA centered at 1.8 microns. We find qualitative differences between the high harmonic spectra of the various organic molecules, and by using benzene as a reference perform comparative studies. Differences are consistent with contributions from multiple electronic states in fluorobenzene, and rapid nuclear motion in methyl-substituted groups.