Yang Yizhang, Hu Xiaoqing, Wu Lu, Wang Zhenpeng, Li Xiaokai, Zhou Shengpeng, Wang Zhenzhen, Guo Fuming, He Lanhai, Luo Sizuo, Zhang Dongdong, Wang Jianguo, Chen Xiangjun, Wu Yong, Wang Chuncheng, Ding Dajun
Institute of Atomic and Molecular Physics, <a href="https://ror.org/00js3aw79">Jilin University</a>, Changchun 130012, China.
National Key Laboratory of Computational Physics, <a href="https://ror.org/03sxpbt26">Institute of Applied Physics and Computational Mathematics</a>, Beijing 100088, China.
Phys Rev Lett. 2024 Sep 13;133(11):113203. doi: 10.1103/PhysRevLett.133.113203.
We extracted the molecular-frame elastic differential cross sections (MFDCSs) for electrons scattering from N_{2}^{+} based on elliptical laser-induced electron diffraction (ELIED), wherein the structural evolution is initialized by the same tunneling ionization and probed by incident angle-resolved laser-induced electron diffraction imaging. To establish ELIED, an intuitive interpretation of the ellipticity-dependent rescattering electron momentum distributions was first provided by analyzing the transverse momentum distribution. It was shown that the incident angle of the laser-induced returning electrons could be tuned within 20° by varying the ellipticity and handedness of the driving laser pulses. Accordingly, the incident angle-resolved DCSs of returning electrons for spherically symmetric targets (Xe^{+} and Ar^{+}) were successfully extracted as a proof-of-principle for ELIED. The MFDCSs for N_{2}^{+} were experimentally obtained at incident angles of 4° and 7°, which were well reproduced by the simulations. The ELIED approach is the only successful method so far for obtaining incident angle-resolved ionic MFDCS, which provides a new sensitive observable for the transient structure retrieval of N_{2}^{+}. Our results suggest that the ELIED has the potential to extract the structural tomographic information of polyatomic molecules with femtosecond and subangstrom spatiotemporal resolutions that can enable the visualization of the nuclear motions in complex chemical reactions as well as chiral recognition.
我们基于椭圆激光诱导电子衍射（ELIED）提取了电子与N₂⁺散射的分子框架弹性微分截面（MFDCSs），其中结构演化由相同的隧穿电离初始化，并通过入射角分辨激光诱导电子衍射成像进行探测。为了建立ELIED，首先通过分析横向动量分布对椭圆率相关的再散射电子动量分布进行了直观解释。结果表明，通过改变驱动激光脉冲的椭圆率和手性，激光诱导返回电子的入射角可在20°范围内调节。因此，作为ELIED原理验证，成功提取了球形对称靶（Xe⁺和Ar⁺）返回电子的入射角分辨微分截面（DCSs）。在4°和7°入射角下通过实验获得了N₂⁺的MFDCSs，模拟结果对其进行了很好的再现。ELIED方法是目前唯一成功获得入射角分辨离子MFDCS的方法，它为N₂⁺的瞬态结构检索提供了一种新的灵敏可观测量。我们的结果表明，ELIED有潜力以飞秒和亚埃时空分辨率提取多原子分子的结构断层信息，从而能够可视化复杂化学反应中的核运动以及手性识别。
