Effect of Electron Initial Longitudinal Velocity on Low-Energy Structure in Above-Threshold Ionization Spectra
WU Ming-Yan1,2, WANG Yan-Lan1,2, LIU Xiao-Jun1**, LI Wei-Dong3, HAO Xiao-Lei4,5, CHEN Jing4,5**
1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 2University of Chinese Academy of Sciences, Beijing 100190 3Department of Physics and Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 4HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871 5Institute of Applied Physics and Computational Mathematics, Beijing 100088
Abstract：Using a semiclassical model, we investigate the effect of the initial longitudinal velocity of the tunnel-ionized electron on low-energy structure (LES) in above-threshold ionization (ATI) spectra. Our analysis shows that the effect (reduction or enhancement) of the initial longitudinal velocity pz0 on the LES is dependent on the direction of the initial longitudinal velocity. For the initial longitudinal velocity along the direction of the laser electric field at the moment of tunneling (i.e., pz0>0), the Coulomb interaction between the photoelectron and ion core is enhanced, while for the initial longitudinal velocity in the opposite direction (i.e., pz0<0), the Coulomb effect is reduced. Our work provides solid evidence that the initial electron longitudinal velocity has considerable effect on the photoelectron dynamics in the ATI process.
2013, Vol. 30 
