近日，华东师范大学孙真荣团队研究了双色飞秒激光脉冲中双电离氩三聚体的三体碎裂。2025年3月13日出版的《物理评论A》杂志发表了这项成果。

利用线偏振双色飞秒激光场和重合测量，课题组实验研究了氩三聚体在双电离后的三体碎裂，产生了两个离子碎片Ar⁺和一个中性碎片Ar。通过分析两个离子片段A r⁺的总动量矢量与其总动能释放之间的相关性，将这个三体通道与原始数据区分开。通过对碎片动能释放的相关谱、牛顿图和达利茨图的详细检查，证实了两种不同的碎片化途径，即协同和顺序的。

通过调节双色激光场的相对相位来操纵来自顺序路径的中性片段的发射方向。观察到的相对相位依赖不对称模式归因于第一步离解中残余Ar₂⁺的增强电离诱导不对称发射。该发现为氩三聚体的离解电离提供了有价值的见解，并有望促进对飞秒激光场中团簇超快动力学的进一步研究。

附：英文原文

Title: Three-body fragmentation of doubly ionized argon trimers in two-color femtosecond laser pulses

Author: Junyang Ma, Shuqi Li, Lei Xiong, Zhubin Hu, Haitao Sun, Yan Yang, Zhenrong Sun

Issue&Volume: 2025/03/13

Abstract: Using linearly polarized two-color femtosecond laser fields and coincidence measurements, we experimentally study the three-body fragmentation of the argon trimer following double ionization, resulting in two ionic fragments, Ar+, and one neutral fragment, Ar. This three-body channel is distinguished from the raw data by analyzing the correlation between the sum momentum vectors of the two ionic fragments Ar+ versus their total kinetic energy releases. Two distinct fragmentation pathways, concerted and sequential, are confirmed by a detailed examination of the kinetic energy releases’ correlation spectra, Newton diagrams, and Dalitz plots of the fragments. The emission directions of the neutral fragments from the sequential pathway are manipulated by adjusting the relative phase of the two-color laser fields. The observed relative phase-dependent asymmetry patterns are attributed to the enhanced ionization induced asymmetric emission of residual Ar2+ in the first dissociation step. Our findings offer valuable insights into the dissociative ionization of argon trimers and are expected to stimulate further research into the ultrafast dynamics of clusters in femtosecond laser fields.

DOI: 10.1103/PhysRevA.111.033110

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.033110