原子电离过程中的干涉效应与库仑场调制机制的研究

项目名称： 原子电离过程中的干涉效应与库仑场调制机制的研究

项目编号： No.11474321

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 赖炫扬

作者单位： 中国科学院武汉物理与数学研究所

项目金额： 84万元

中文摘要： 原子电离是强激光驱动下原子体系发生的基本物理过程，是理解其他原子强场现象，如高次谐波辐射和阿秒物理等的基础。在原子电离过程中，不同时刻发生的电离事件会相互干涉，影响原子电离行为，例如，在光电子能谱上出现干涉条纹。目前人们对原子电离干涉效应的理解还不够深入，主要原因是，人们为了简化计算，采用强场近似理论研究原子电离干涉效应，这一理论忽略了原子实的库仑场对电离电子的影响。最近许多研究工作发现库仑场的存在对原子电离干涉具有重要的影响，如，扭曲光电子能谱中的干涉条纹。然而，库仑场对原子电离干涉现象的影响机制是什么，诸如此更深入的问题尚未研究清楚。本项目拟研究库仑场对原子电离干涉的影响及其机制：结合库仑场修正的强场近似理论，研究原子电离的光电子能谱，分析在库仑场和激光场共同作用下的电子电离轨道，以及各个轨道之间相互干涉引起的原子电离行为变化，揭示原子电离干涉现象中的库仑场效应及其机制。

中文关键词： 强激光场；原子电离；量子干涉；库仑场；电子轨道

英文摘要： Atomic ionization by strong laser fields is one of the basic processes in strong field physics and is fundamental to the understanding of other strong-field phenomena, such as high-order harmonic generation and attosecond physics. During the ionization of atom in strong laser fields, the ionization events occurring at different times interfere each other, which affects the atomic ionization and results in an interference pattern in the photoelectron spectrum. Currently, the research of the interference effect in the atomic ionization is not deep enough. The reason is that the interference effect is usually investigated with strong field approximation (SFA) theory which fully disregards the influence of the Coulomb potential on the ionized electron for simplification. Recently, many studies show that the Coulomb potential has great impact on the interference effect in the atomic ionization. For example, it can distort the interference pattern in the photoelectron spectrum. However, the mechanism of the influence of the Coulomb potential on the interference effect in the ionization has not yet been sufficiently explained. In this project, we will study the photoelectron spectrum in the terms of a Coulomb-corrected strong field approximation (CCSFA) theory. We will analyze the electron trajectories in the Coulomb potential and the laser fields, as well as the interference effect of the trajectories on the atomic ionization, to uncover the mechanism of the influence of the Coulomb potential on the interference effect in the atomic ionization.

英文关键词： Strong laser fields;atomic ionization;quantum interference;Coulom potential;electron trajectory