Impact of two-electron dynamics and correlations on high-order harmonic generation in He

Abstract

The interaction of a helium atom with intense short 800 nm laser pulse is studied theoretically beyond the single-active-electron approximation. For this purpose, the time-dependent Schrödinger equation for the two-electron wave packet driven by a linearly-polarized infrared pulse is solved by the time-dependent restricted-active-space configuration-interaction method (TD-RASCI) in the dipole velocity gauge. By systematically extending the space of active configurations, we investigate the role of the collective two-electron dynamics in the strong field ionization and high-order harmonic generation (HHG) processes. Our numerical results demonstrate that allowing both electrons in He to be dynamically active results in a considerable extension of the computed HHG spectrum.

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References in corpus (2)

• Quantitative Rescattering Theory for high-order harmonic generation from molecules
• Time-dependent generalized-active-space configuration-interaction approach to photoionization dynamics of atoms and molecules

Cited by in corpus (3)

• Photoelectron circular dichroism in the multiphoton ionization by short laser pulses: III. Photoionization of fenchone in different regimes
• Impact of intense laser pulses on the autoionization dynamics of the 2s2p doubly-excited state of He
• Effects of electronic correlation on the high harmonic generation in helium: a time-dependent configuration interaction singles vs time-dependent full configuration interaction study