WikiEdge:ArXiv速递/2025-02-17

摘要

• 原文标题：Femtosecond-and-atom-resolved solvation dynamics of a Na$^+$ ion in a helium nanodroplet
• 中文标题：氦纳米液滴中钠离子的飞秒和原子级分辨溶剂化动力学
• 发布日期：2025-02-17 13:17:09+00:00
• 作者：Simon H. Albrechtsen, Jeppe K. Christensen, Christian E. Petersen, Constant A. Schouder, Pedro Javier Carchi-Villalta, Iker Sánchez-Pérez, Massimiliano Bartolomei, Tomás González-Lezana, Fernando Pirani, Henrik Stapelfeldt
• 分类：physics.atm-clus
• 原文链接：http://arxiv.org/abs/2502.11783v1

原文摘要：Recently, it was shown how the primary steps of solvation of a single Na$^+$ ion, instantly created at the surface of a nanometer-sized droplet of liquid helium, can be followed at the atomic level [Albrectsen et al. Nature $\textbf{623}$, 319 (2023)]. This involved measuring, with femtosecond time resolution, the gradual attachment of individual He atoms to the Na$^+$ ion as well as the energy dissipated from the local region of the ion. In the current work, we provide a more comprehensive and detailed description of the experimental findings of the solvation dynamics, and present an improved Poisson-statistical analysis of the time-resovled yields of the solvation complexes, Na$^+$He$_n$. For droplets containing an average of 5200 He atoms, this analysis gives a binding rate of $1.84\pm0.09$ atoms/ps for the binding of the first five He atoms to the Na$^+$ ion. Also, thanks to accurate heoretical values for the evaporation energies of the Na$^+$He$_n$ complexes, obtained by Path Integral Monte Carlo methos using a new potential energy surface presented here for the first time, we improved the determination of the time-dependent removal of the solvation energy from the region around the sodium ion. We find that it follows Newton's law of cooling for the first 6 ps. Measurements were carried out for three different average droplet sizes, $\langle N_D\rangle = $ 9000, 5200 and 3600 helium atoms, and differences between these results are discussed. 中文摘要：最近的研究展示了如何在原子水平上跟踪单个Na$^+$离子在纳米级液氦液滴表面瞬间形成时的溶剂化初始步骤 [Albrectsen et al. Nature $\textbf{623}$, 319 (2023)]。这包括以飞秒时间分辨率测量单个He原子逐渐附着到Na$^+$离子的过程，以及从离子局部区域耗散的能量。在当前的工作中，我们提供了对溶剂化动力学实验结果的更全面和详细的描述，并对溶剂化复合物Na$^+$He$_n$的时间分辨产率进行了改进的泊松统计分析。对于平均含有5200个He原子的液滴，该分析得出前五个He原子与Na$^+$离子结合的结合速率为$1.84\pm0.09$原子/皮秒。此外，得益于通过路径积分蒙特卡罗方法获得的新势能面，我们首次获得了Na$^+$He$_n$复合物的蒸发能量的精确理论值，从而改进了对钠离子周围区域溶剂化能量随时间去除的测定。我们发现，在前6皮秒内，它遵循牛顿冷却定律。测量在三种不同平均液滴尺寸下进行，$\langle N_D\rangle = $ 9000、5200和3600个氦原子，并讨论了这些结果之间的差异。