电子纵向初速度在氢原子蜘蛛状动量谱干涉结构中的作用  

Initial longitudinal velocity resolved spiderlike photoelectron momentum distributions in hydrogen

作　　者：何宇飞 张贵忠[1] 付国跃 盛泉[1] 史伟[1] 姚建铨[1] He Yu-Fei;Zhang Gui-Zhong;Fu Guo-Yue;Sheng Quan;Shi Wei;Yao Jian-Quan(Key Laboratory of Optoelectronic Information Technology,Ministry of Education,College of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,光电信息技术教育部重点实验室,天津300072

出　　处：《物理学报》2022年第18期131-139,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11674243);国家重点研发计划(批准号:2017YFB1401201)资助的课题。

摘　　要：使用半经典回碰模型和求解含时薛定谔方程的方法,数值研究了电离电子的纵向初速度在氢原子的蜘蛛状动量谱干涉结构中的作用.对光电子动量谱的纵向和横向动量分布性质的数值研究结果表明,可以从光电子动量谱的纵向动量分布获取电离电子纵向初速度的信息.研究发现,无论将初速度视为多个常数亦或是多段分布,均能重建完整的蜘蛛状干涉结构,可见用常数值来描述电子的初速度有待深入研究.另外,数值求解含时薛定谔方程的结果也与半经典回碰模型的模拟结论相一致,可以互相印证.本文的研究结果表明,纵向初速度在强激光脉冲电离产生的光电子动量谱中起着重要作用,速度的分布情况还需结合非绝热过程深入研究.Tunneling ionization of atoms is the basis of many phenomena and techniques,which requires people to be able to comprehensively understand this crucial physical process.Recent experiments have demonstrated the existence of the nonzero initial longitudinal momentum spread at the tunnel exit.However,the initial longitudinal velocity is usually set to be zero in the adiabatic regime.In this work,we numerically study that the initial longitudinal velocity of ionized-out electrons plays the role in the spiderlike photoelectron momentum distributions in hydrogen atom by using the semiclassical rescattering model and the time-dependent Schr?dinger equation.Nonzero longitudinal initial velocity,no matter whether it is an offset or an offset distribution,is considered in the semiclassical rescattering model.Longitudinal cut-plot and transverse cut-plot of the photoelectron momentum distribution are discussed.The final longitudinal momentum of the electron is found to be sensitive to the initial longitudinal velocity,which offers us a method of determining the information about the initial longitudinal velocity from a photoelectron momentum distribution according to this linear relationship.We unveil that either an offset or an offset distribution for the initial longitudinal velocity can perfectly reproduce the same spiderlike photoelectron momentum distributions.The semiclassical results are backed by the full quantum simulation.It is expected that more precise research is required to deepen the knowledge of the initial longitudinal velocity in strong field ionization of atoms.

关 键 词：半经典回碰模型 光电子动量谱 纵向初速度 蜘蛛状干涉结构 

分 类 号：O562[理学—原子与分子物理]