dorsal/arxiv
View SchemaEffective ATI Channels in High Harmonic Generation
| Authors | M. Yu. Kuchiev, V. N. Ostrovsky |
|---|---|
| Categories | |
| ArXiv ID | physics/0007016 |
| URL | https://arxiv.org/abs/physics/0007016 |
| DOI | 10.1088/0953-4075/34/3/317 |
Abstract
Harmonic generation by an atom in a laser field is described by the three-step mechanism as proceeding via above-threshold ionization (ATI) followed by the electron propagation in the laser-dressed continuum and the subsequent laser assisted recombination (LAR). An amplitude of harmonic production is given by the coherent sum of contributions from different intermediate ATI channels labeled by the number m of absorbed laser photons. The range of m-values that gives substantial contribution is explored and found to be rather broad for high harmonic generation. The coherence effects are of crucial importance being responsible for the characteristic pattern of harmonic intensities with a plateau domain followed by a cutoff region. Due to multiphoton nature of the process, an efficient summation of m-contributions can be carried out in the framework of the saddle point method. The saddle points correspond to some complex-valued labels m=m_c associated with the intermediate effective ATI channels in the three-step harmonic generation process. The advantage of this approach stems from the fact that summation over large number of conventional ATI m-channels is replaced by summation over small number of effective m_c-channels. The equation governing m_c has a transparent physical meaning: the electron ejected from the atom on the first (ATI) stage should return to the core to make LAR possible. The calculated rates are in good agreement with the results obtained by other approaches.
{
"annotation_id": "83b048a5-84a0-4ab3-bd71-953981fe0498",
"date_created": "2026-03-02T18:00:32.762000Z",
"date_modified": "2026-03-02T18:00:32.762000Z",
"file_hash": "392969054a25b80475f65c92d08104e1121e3507cfd655f88c30c8b219a2c593",
"private": false,
"record": {
"abstract": "Harmonic generation by an atom in a laser field is described by the\nthree-step mechanism as proceeding via above-threshold ionization (ATI)\nfollowed by the electron propagation in the laser-dressed continuum and the\nsubsequent laser assisted recombination (LAR). An amplitude of harmonic\nproduction is given by the coherent sum of contributions from different\nintermediate ATI channels labeled by the number m of absorbed laser photons.\nThe range of m-values that gives substantial contribution is explored and found\nto be rather broad for high harmonic generation. The coherence effects are of\ncrucial importance being responsible for the characteristic pattern of harmonic\nintensities with a plateau domain followed by a cutoff region. Due to\nmultiphoton nature of the process, an efficient summation of m-contributions\ncan be carried out in the framework of the saddle point method. The saddle\npoints correspond to some complex-valued labels m=m_c associated with the\nintermediate effective ATI channels in the three-step harmonic generation\nprocess. The advantage of this approach stems from the fact that summation over\nlarge number of conventional ATI m-channels is replaced by summation over small\nnumber of effective m_c-channels. The equation governing m_c has a transparent\nphysical meaning: the electron ejected from the atom on the first (ATI) stage\nshould return to the core to make LAR possible. The calculated rates are in\ngood agreement with the results obtained by other approaches.",
"arxiv_id": "physics/0007016",
"authors": [
"M. Yu. Kuchiev",
"V. N. Ostrovsky"
],
"categories": [
"physics.atom-ph"
],
"doi": "10.1088/0953-4075/34/3/317",
"title": "Effective ATI Channels in High Harmonic Generation",
"url": "https://arxiv.org/abs/physics/0007016"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "938ec014-300a-416c-aca5-53c0f74fdc8a",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}