Hansen, Jonas Lerche10; Holmegaard, Lotte11; Kalhøj, Line7; Kragh, Sofie Louise7; Stapelfeldt, Henrik12; Filsinger, Frank9; Meijer, Gerard9; Küpper, Jochen9; Dimitrovski, Darko11; Abu-Samha, Mahmoud3; Martiny, Christian P. J.3; Madsen, Lars Bojer11
1 Interdisciplinary Nanoscience Center, Faculty of Science, Aarhus University, Aarhus University2 Department of Chemistry, Faculty of Science, Aarhus University, Aarhus University3 Department of Physics and Astronomy, Faculty of Science, Aarhus University, Aarhus University4 Teoretisk naturvidenskab, Aarhus University, Aarhus University5 iNano-School, Science and Technology, Aarhus University6 Department of Physics and Astronomy, Science and Technology, Aarhus University7 Kemisk Institut, Aarhus Universitet8 Department of Chemistry, Science and Technology, Aarhus University9 Fritz-Haber-Institut der Max-Planck-Gesellschaft10 iNano-School, Science and Technology, Aarhus University11 Department of Physics and Astronomy, Science and Technology, Aarhus University12 Department of Chemistry, Science and Technology, Aarhus University
We present a combined experimental and theoretical study on strong-field ionization of a three-dimensionally-oriented asymmetric top molecule, benzonitrile (C7H5N), by circularly polarized, nonresonant femtosecond laser pulses. Prior to the interaction with the strong field, the molecules are quantum-state selected using a deflector and three-dimensionally (3D) aligned and oriented adiabatically using an elliptically polarized laser pulse in combination with a static electric field. A characteristic splitting in the molecular frame photoelectron momentum distribution reveals the position of the nodal planes of the molecular orbitals from which ionization occurs. The experimental results are supported by a theoretical tunneling model that includes and quantifies the splitting in the momentum distribution. The focus of the present article is to understand strong-field ionization from 3D-oriented asymmetric top molecules, in particular the suppression of electron emission in nodal planes of molecular orbitals. In the preceding article [Dimitrovski et al., Phys. Rev. A 83, 023405 (2011)] the focus is to understand the strong-field ionization of one-dimensionally-oriented polar molecules, in particular asymmetries in the emission direction of the photoelectrons.
Physical Review a (atomic, Molecular and Optical Physics), 2011, Vol 83, Issue 2