748 research outputs found
Interplay of polarization geometry and rotational dynamics in high harmonic generation from coherently rotating linear molecule
Recent reports on intense-field pump-probe experiments for high harmonic
generation from coherently rotating linear molecules, have revealed remarkable
characteristic effects of the simultaneous variation of the polarization
geometry and the time delay on the high harmonic signals. We analyze the
effects and give a unified theoretical account of the experimental observationsComment: 4 pages, 5 figure
Multiphoton excitations in vibrational rotational states of diatomic molecules in intense electromagnetic field
A theory is presented and a calculational procedure is outlined for evaluating transition amplitudes of multiphoton excitations of vibrational-rotational levels in diatomic molecules. This theory can be utilized in studying behavior of molecules in intense electromagnetic fields
Vibro-rotational excitations of H2/+/ by e/+/ impact - A semi-classical approach
Semiclassical approach to vibrorotational excitations of H2/+/ by positron impac
Geometric phases in open tripod systems
We first consider stimulated Raman adibatic passages (STIRAP) in a closed
four-level tripod system. In this case, the adiabatic eigenstates of the system
acquire real geometric phases. When the system is open and subject to
decoherence they acquire complex geometric phases that we determine by a Monte
Carlo wave function approach. We calculate the geometric phases and the state
evolution in the closed as well as in the open system cases and describe the
deviation between these in terms of the phases acquired. When the system is
closed, the adiabatic evolution implements a Hadamard gate. The open system
implements an imperfect gate and hence has a fidelity below unity. We express
this fidelity in terms of the acquired geometric phases.Comment: 10 pages 7 figure
Quantum signatures in laser-driven relativistic multiple-scattering
The dynamics of an electronic Dirac wave packet evolving under the influence
of an ultra-intense laser pulse and an ensemble of highly charged ions is
investigated numerically. Special emphasis is placed on the evolution of
quantum signatures from single to multiple scattering events. We quantify the
occurrence of quantum relativistic interference fringes in various situations
and stress their significance in multiple-particle systems, even in the
relativistic range of laser-matter interaction.Comment: 4 pages, 2 figures, LaTeX, revtex
Wavelength and intensity dependence of multiple forward scattering at above-threshold ionization in mid-infrared strong laser fields
The nonperturbative role of multiple forward scattering for Coulomb focusing
in mid-infrared laser fields and its dependence on a laser intensity and
wavelength are investigated for low-energy photoelectrons at above-threshold
ionization. We show that high-order rescattering events can have comparable
contributions to the Coulomb focusing and the effective number of rescattering
depends weakly on laser parameters in the classical regime. However, the
relative contribution of the forward scattering to the Coulomb focusing and the
Coulomb focusing in total decrease with the rise of the laser intensity and
wavelength
- …