Efficient variable time-stepping scheme for intense field-atom interactions

Journal Article · Mon Mar 01 00:00:00 EST 1993 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.47.1852· OSTI ID:6702628

Cerjan, C ^[1]; Kosloff, R ^[2]

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. The Fritz Haber Research Center for Molecular Dynamics, The Hebrew University, Jerusalem 91904 (Israel)

The recently developed Residuum method [Tal-Ezer, Kosloff, and Cerjan, J. Comput. Phys. 100, 179 (1992)], a Krylov subspace technique with variable time-step integration for the solution of the time-dependent Schroedinger equation, is applied to the frequently used soft Coulomb potential in an intense laser field. This one-dimensional potential has asymptotic Coulomb dependence with a softened'' singularity at the origin; thus it models more realistic phenomena. Two of the more important quantities usually calculated in this idealized system are the photoelectron and harmonic photon generation spectra. These quantities are shown to be sensitive to the choice of a numerical integration scheme: some spectral features are incorrectly calculated or missing altogether. Furthermore, the Residuum method allows much larger grid spacings for equivalent or higher accuracy in addition to the advantages of variable time stepping. Finally, it is demonstrated that enhanced high-order harmonic generation accompanies intense field stabilization and that preparation of the atom in an intermediate Rydberg state leads to stabilization at much lower laser intensity.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6702628
• Journal Information: Physical Review A; (United States), Vol. 47:3; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
PHOTON-ATOM COLLISIONS
SCHROEDINGER EQUATION
ANALYTICAL SOLUTION
COULOMB FIELD
HARMONIC GENERATION
LASERS
PHOTOEMISSION
TIME DEPENDENCE
ATOM COLLISIONS
COLLISIONS
DIFFERENTIAL EQUATIONS
ELECTRIC FIELDS
EMISSION
EQUATIONS
FREQUENCY MIXING
PARTIAL DIFFERENTIAL EQUATIONS
PHOTON COLLISIONS
SECONDARY EMISSION
WAVE EQUATIONS
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)