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Title: Ionization and high-order harmonic generation in aligned benzene by a short intense circularly polarized laser pulse

Journal Article · · Physical Review. A
 [1];  [2]; ;  [3]
  1. Institute of Chemistry and the Lise Meitner Center for Quantum Chemistry, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)
  2. Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90025 (United States)
  3. Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

We present a first-principles study of ionization and high-order harmonic generation by benzene aligned in the polarization plane of a short circularly polarized laser pulse. Time-dependent density-functional theory within the adiabatic local-density approximation is employed to describe the 30 valence-electron dynamics in three dimensions. The multielectron approach enables us to study the effect of very strong laser fields, 10{sup 14}-10{sup 15} W cm{sup -2}, where multiple ionization and high-order harmonic generation interplay. Large ionization currents are formed, causing ionization of 1-4 electron charges, while strong high-order harmonic generation is observed. The well-known recollision mechanism of high-order harmonic generation plays a part for moderate laser intensities but is fully suppressed for strong laser fields. The harmonic generation spectra are characterized by two distinguishable plateaus, where the structure of the first plateau is dominated by the 6k{+-}1 (k=0,1,...) selection rule. The number of harmonics in the second plateau is insensitive to the duration of the pulse. The peaks appear in pairs or in threesomes, depending on the pulse duration.

OSTI ID:
20640355
Journal Information:
Physical Review. A, Vol. 68, Issue 4; Other Information: DOI: 10.1103/PhysRevA.68.043406; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English