Kramers–Henneberger Form of Strong Field Theory with the Correction of Dipole Approximation  

作　　者：Yi-Ning Huo Jian Li Feng-Cai Ma 霍一宁;李健;马凤才(School of Physics, Liaoning University;School of Physical Science and Technology, Inner Mongolia University;Department of Science, Shenyang Aerospace University)

机构地区：[1]School of Physics, Liaoning University, Shenyang 110036 [2]School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021 [3]Department of Science, Shenyang Aerospace University, Shenyang 110036

出　　处：《Chinese Physics Letters》2018年第4期25-29,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 11274149 and 11304185;the Program of Shenyang Key Laboratory of Optoelectronic Materials and Technology under Grant No F12-254-1-00

摘　　要：We show that the breakdown of dipole approximation can be adopted to explain the asymmetry structure in the photoelectron momentum distributions along the beam propagation direction, which is defined as the photoelectron longitudinal momentum distributions（PLMD）, in tunneling regime（K ？ 1）, based on the strong field approximation theory. The nondipole Hamiltonian for photoelectrons interacting with laser fields from a hydrogen-like atom is transformed into the Kramers–Henneberger frame in our model. To introduce the correction of dipole approximation, the spatial variable is kept in a vector potential （r, t）, demonstrating that the breakdown of dipole approximation is the major reason for the shift of the peak in PLMD. The nondipole effects are apparent when circularly polarized lasers are adopted to ionize the atoms, and clear tendency to increase offsets is found for increasing laser intensities.We show that the breakdown of dipole approximation can be adopted to explain the asymmetry structure in the photoelectron momentum distributions along the beam propagation direction, which is defined as the photoelectron longitudinal momentum distributions（PLMD）, in tunneling regime（K ？ 1）, based on the strong field approximation theory. The nondipole Hamiltonian for photoelectrons interacting with laser fields from a hydrogen-like atom is transformed into the Kramers–Henneberger frame in our model. To introduce the correction of dipole approximation, the spatial variable is kept in a vector potential （r, t）, demonstrating that the breakdown of dipole approximation is the major reason for the shift of the peak in PLMD. The nondipole effects are apparent when circularly polarized lasers are adopted to ionize the atoms, and clear tendency to increase offsets is found for increasing laser intensities.

关 键 词：exp KRAMERS 

分 类 号：O43[机械工程—光学工程]