| Cite this article as: Tong Xiao-Gang,Xue Yu-Feng,Zhang Zhi-Guo,Yang Shu-Ping. Study on the strong field approximation method for above threshold ionization of atom in laser field [J]. J. At. Mol. Phys.(原子与分子物理学报), 2025, 42: 024002 (in Chinese) |
| Study on the strong field approximation method for above threshold ionization of atom in laser field |
| Hits 197 Download times 193 Received:June 14, 2023 Revised:July 03, 2023 |
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| DOI
10.19855/j.1000-0364.2025.024002 |
| Key Words
Above-threshold ionization Strong field approximation Schrödinger equation Time evolution operator Saddle point approximation. |
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| Abstract
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| The basic phenomenon of the interaction between intense laser and atom is ionization of atom, among which the above-threshold ionization is a very important phenomenon. Many methods have been used to study the properties of above-threshold ionization of atom in laser field, and the strong field approximation method is one of the very important theoretical methods. In this paper, the second order strong field approximation theory under perturbation theory is derived by using the time evolution operator and saddle point approximation method, the first order approximation term gives the direct ionization amplitude of low energy electron, the second order approximation term describes the rescattering process of electron and parention, and represents the ionization amplitude of high energy photoelectron. The photoelectron spectra and ionization probability of single atom in linearly polarized laser field are given, which provides a theoretical reference and basis for the simulation and study of the kinetic behavior of atoms in laser field under the strong field approximation theory. |
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