High-order-harmonic spectra from atoms in intense laser fields: Exact versus approximate methods

Pugliese, Salvatore; Simonsen, Aleksander Skjerlie; Førre, Morten; Hansen, J. P.

doi:10.1103/physreva.92.023424

“…where σ 0 = σ (t 0 ; t 0 ) is therefore the initial standard deviation, immediately after the ionization step. Note that our definition of the SCWF naturally avoids the singularity of the standard deviation for t → t 0 as is typically observed using the stationary phase approximation [26,27]. Numerically we find that in the SFA the SCWF approximation offers very good results compared to the full quantum dynamics.…”

Section: A Electronic Trajectorymentioning

confidence: 56%

“…In most theoretical analyses and interpretations of HHG, two main approaches have been considered in the literature. On the one hand, the plane wave/Volkov state (or further refined Coulomb corrected models) [21,26,27] adopt a wave perspective of the recolliding electron. Such an approach allows one to define the recollision dipole element [see, e.g., Eq.…”

Section: Introductionmentioning

confidence: 99%

Semiclassical-wave-function perspective on high-harmonic generation

Mauger

¹

,

Abanador

²

,

Lopata

³

et al. 2016

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We introduce a semi-classical wavefunction (SCWF) model for strong-field physics and attosecond science. When applied to high harmonic generation (HHG), this formalism allows one to show that the natural time-domain separation of the contribution of ionization, propagation and recollisions to the HHG process leads to a frequency-domain factorization of the harmonic yield into these same contributions, for any choice of atomic or molecular potential. We first derive the factorization from the natural expression of the dipole signal in the temporal domain by using a reference system, as in the quantitative rescattering (QRS) formalism [J. Phys. B. 43, 122001 (2010)]. Alternatively, we show how the trajectory component of the SCWF can be used to express the factorization, which also allows one to attribute individual contributions to the spectrum to the underlying trajectories.

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“…where σ 0 = σ (t 0 ; t 0 ) is therefore the initial standard deviation, immediately after the ionization step. Note that our definition of the SCWF naturally avoids the singularity of the standard deviation for t → t 0 as is typically observed using the stationary phase approximation [26,27].…”

Section: A Electronic Trajectorymentioning

confidence: 96%

Semi-Classical Wavefunction Perspective to High-Harmonic Generation

Mauger,

Abanador,

Lopata

et al. 2015

Preprint

0

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We introduce a semi-classical wavefunction (SCWF) model for strong-field physics and attosecond science. When applied to high harmonic generation (HHG), this formalism allows one to show that the natural time-domain separation of the contribution of ionization, propagation and recollisions to the HHG process leads to a frequency-domain factorization of the harmonic yield into these same contributions, for any choice of atomic or molecular potential. We first derive the factorization from the natural expression of the dipole signal in the temporal domain by using a reference system, as in the quantitative rescattering (QRS) formalism [J. Phys. B. 43, 122001 (2010)]. Alternatively, we show how the trajectory component of the SCWF can be used to express the factorization, which also allows one to attribute individual contributions to the spectrum to the underlying trajectories.

show abstract

“…On the other hand, the ionized electron component is described with a oneelectron continuum, which we generically label with |v . Depending on the degree of precision required, one can use, e.g., plane waves/Volkov states, Coulomb waves [56], exact one-electron continuum states [57].…”

Section: B Single-ionization Effective Modelmentioning

confidence: 99%

Signature of charge migration in modulations of double ionization

Mauger

¹

,

Abanador

²

,

Bruner

³

et al. 2018

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We present a theoretical investigation of charge migration following strong-field ionization in a multi-electron system. We study a model homo-nuclear molecule with two electrons, each restricted to one dimension (1+1D), interacting with a strong, static electric field. We show that in this system charge migration results from the interplay between multiple ionization channels that overlap in space, creating a coherent electron-hole wave packet in the cation. We also find that, in our case, charge migration following the first ionization manifests as a modulation of the subsequent double ionization signal. We derive a parametrized semiclassical model from the full multi-electron system and we discuss the importance of the choice of cation electronic-structure basis for the efficacy of the semiclassical representation. We use the ab-initio solution of the full 1+1D system as a reference for the qualitative and quantitative results of the parametrized semiclassical model. We discuss the extension of our model to long wavelength time-dependent fields with full dimension, many-electron targets.

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High-order-harmonic spectra from atoms in intense laser fields: Exact versus approximate methods

Cited by 5 publications

References 34 publications

Semiclassical-wave-function perspective on high-harmonic generation

Semiclassical-wave-function perspective on high-harmonic generation

Semi-Classical Wavefunction Perspective to High-Harmonic Generation

Signature of charge migration in modulations of double ionization

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