用解析修正的半经典回碰模型研究蜘蛛状动量谱中的库仑位移

Coulomb Shifts in Spiderlike Photoelectron Momentum Distributions by Analytically-Coulomb-Corrected Semiclassical Rescattering Model

报道了强激光脉冲电离氢原子诱导的蜘蛛状干涉光电子动量谱(PMD)的数值探究结果。标准的半经典回碰模型(SRM)虽然简化了电子行为,但是忽略了难以处理的库仑作用。与以往的数值修正不同,对电离过程的库仑作用进行解析近似处理,并将其引入到SRM中,成功构建了解析修正的SRM(ACSRM)。运用该模型数值模拟计算了蜘蛛状PMD和库仑作用引起的干涉图样的系统性位移。用经典相位、含时薛定谔方程(TDSE)和电子轨迹等方法,对这种位移现象进行了定量分析和机理探究。结果发现,所提的经典相位方法对PMD中蜘蛛状干涉结构的库仑作用最敏感,对第一干涉极小值尤为突出。精确的TDSE数值结果也证实了由ACSRM所得到的模拟结果的正确性。

This paper presents numerical results on the spiderlike photoelectron momentum distributions(PMDs)induced by the ionization of hydrogen atoms by an intense laser pulse.In addition,although the standard semiclassical rescattering model(SRM)has simplified actions of electrons,it fails to take complex Coulomb interaction into account.Different from existing numerical correction,this paper carries out an analytical approximate treatment of Coulomb interaction during the ionization,introduces it into SRM,and successfully constructs an analyticallyCoulombcorrected SRM(ACSRM).Based on ACSRM,the systematic shifts of interference patterns caused by spiderlike PMDs and Coulomb interaction are simulated and calculated.Furthermore,through the classical phase,timedependent Schrödinger equation(TDSE),electron orbit,and other methods,this paper quantitatively analyzes the shifts and explores the corresponding mechanism.The results show that the proposed classical phase method is the most sensitive to the Coulomb interaction in the spiderlike PMDs,especially to the first interference minima,and the accurate TDSE values verify the correctness of simulated results obtained by ACSRM.