Momentum distributions of symmetric(H_(2)^(+))and asymmetric(HeH^(2+))molecular ions in a circularly polarized laser field under different ionization mechanisms  

作　　者：Xin-Yu Hao Shu-Juan Yan Ying Guo Jing Guo 郝欣宇;闫淑娟;郭颖;郭静(Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China)

机构地区：[1]Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China

出　　处：《Chinese Physics B》2024年第12期258-263,共6页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Jilin Province(Grant No.20220101010JC);the National Natural Science Foundation of China(Grant No.12074146)。

摘　　要：By numerically solving the two-dimensional(2D)time-dependent Schrödinger equation(TDSE),we present photoelectron momentum distributions(PMDs)and photoelectron angular distributions(PADs)of symmetric(H_(2)^(+))and asymmetric(HeH^(2+))molecular ions in circularly polarized(CP)laser pulses.By adjusting the laser wavelength,two circumstances of resonance excitation and direct ionization were considered.The ionization mechanism of the resonance excitation was mainly investigated.The results show that the PMDs of H_(2)^(+) and HeH^(2+) in the y-direction gradually increase with increasing intensity,and the number of PMDs lobes is in good agreement with the results predicted by the ultrafast ionization model.In the resonance excitation scenario,the PMDs of are dominated by two-photon ionization,whereas the PMDs of HeH_(2)^(+) are dominated by three-photon ionization.Furthermore,the PMDs of HeH^(2+)are stronger in the resonance excitation scenario than those of H_(2)^(+),which can be explained by the time-dependent population of electrons.In addition,the molecular structure is clearly imprinted onto the PMDs.

关 键 词：resonance excitation time-dependent Schrödinger equation ultrafast ionization model photoelectron momentum distributions 

分 类 号：TN24[电子电信—物理电子学] O56[理学—原子与分子物理]