Transition from SAMO to Rydberg State Ionization in C60 in Femtosecond Laser Fields
| Autor: | K. J. Betsch, Hui Li, Benoît Mignolet, Françoise Remacle, C. L. Cocke, I. Ben-Itzhak, K. D. Carnes, Zhenhua Wang, Matthias F. Kling |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Letter
Chemistry 02 engineering and technology 021001 nanoscience & nanotechnology Kinetic energy Laser 01 natural sciences Spectral line law.invention symbols.namesake law Ionization 0103 physical sciences Femtosecond Physics::Atomic and Molecular Clusters Rydberg formula symbols General Materials Science Density functional theory Physics::Atomic Physics Physical and Theoretical Chemistry Rydberg state Atomic physics 010306 general physics 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry Letters |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.6b02139 |
| Popis: | The transition between two distinct ionization mechanisms in femtosecond laser fields at 785 nm is observed for C60 molecules. The transition occurs in the investigated intensity range from 3 to 20 TW/cm2 and is visualized in electron kinetic energy spectra below the one-photon energy (1.5 eV) obtained via velocity map imaging. Assignment of several observed broad spectral peaks to ionization from superatom molecular orbitals (SAMOs) and Rydberg states is based on time-dependent density functional theory simulations. We find that ionization from SAMOs dominates the spectra for intensities below 5 TW/cm2. As the intensity increases, Rydberg state ionization exceeds the prominence of SAMOs. Using short laser pulses (20 fs) allowed uncovering of distinct six-lobe photoelectron angular distributions with kinetic energies just above the threshold (below 0.2 eV), which we interpret as over-the-barrier ionization of shallow f-Rydberg states in C60. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|