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Your search keyword '"*HELIUM hydrides"' showing total 2 results
Start Over Descriptor "*HELIUM hydrides" Topic harmonic generation
2 results on '"*HELIUM hydrides"'

1. Theoretical investigation of high-order harmonic generation from asymmetric molecular ions in the chirped laser field.

Author

Cui, Hui-Fang, Xia, Chang-Long, and Miao, Xiang-Yang

Subjects
*HARMONIC generation, *HELIUM hydrides, *PROBABILITY theory, *QUANTUM mechanics, *SCHRODINGER equation
Abstract

High-order harmonic generation from the asymmetric helium hydrogen molecular ion exposed to a few-cycle chirped laser field is theoretically investigated by numerically solving the reduced one-dimension non-Born–Oppenheimer time dependent Schrödinger equation. The numerical results show that the plateau of the high-order harmonic spectrum is dramatically broadened and smoother with the introduction of the chirp. Further study presents that only the short quantum path contributes to harmonic emission and the long quantum path disappears in the chirped laser. In addition, an 80-as isolated attosecond pulse is obtained by superposing the harmonics from the 100th to the 130th order in the chirped field. The time-frequency distributions and the electronic probability distributions are presented to explain the underlying physical mechanism. [ABSTRACT FROM AUTHOR]

Published
2016
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2. Orientation dependence of harmonic emission from vibrating HeH2+ versus HeT2+: Effects of a permanent dipole.

Author

Li, Y. P., Yu, S. J., Li, W. Y., and Chen, Y. J.

Subjects
*HELIUM hydrides, *HARMONIC generation, *SCHRODINGER equation
Abstract

We study high-order harmonic generation (HHG) from the oriented asymmetric molecule HeH2+ and its isotopic variant HeT2+ in strong few-cycle laser pulses, by numerically solving the non-Born-Oppenheimer time-dependent Schrödinger equation. Our simulations show that the influence of nuclear motion on HHG of the asymmetric system is dependent on the molecular orientation and the laser parameters. At relatively weak laser intensities, the HHG yields of HeH2+ are higher than those of HeT2+ for the parallel orientation and the situation reverses for the perpendicular orientation. However, at high laser intensities, they become comparable for the parallel case. With a developed simple HHG model that considers the influences of nuclear motion on all of the ionization, propagation, and recombination processes of HHG, we show the permanent dipole of the system plays an important role in these phenomena. Our results shed light on the complex dynamics of the asymmetric system in strong laser fields. [ABSTRACT FROM AUTHOR]

Published
2017
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