Oriented Polar Molecules Trapped in Cold Helium Nanodropets: Electrostatic Deflection, Size Separation, and Charge Migration
Oriented Polar Molecules Trapped in Cold Helium Nanodropets: Electrostatic Deflection, Size Separation, and Charge Migration
复制标题
冷氦纳米液滴中捕获的定向极性分子：静电偏转、尺寸分离和电荷迁移
DOI：
10.1103/physrevlett.123.043203
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发表时间：
2019
影响因子：
8.6
通讯作者：
Kresin, Vitaly V.
中科院分区：
文献类型：
--
作者：
Niman, John W.;Kamerin, Benjamin S.;Merthe, Daniel J.;Kranabetter, Lorenz;Kresin, Vitaly V.
通过静电偏转研究了掺杂极性分子的氦纳米液滴。这种广泛适用的方法甚至允许多原子分子在现场达到亚开尔文温度和几乎完全取向。场梯度产生的强大力甚至会强烈偏转具有数万个原子的液滴，这是光束“偏转测量法”研究的最大的中性系统。我们使用偏转来提取液滴尺寸分布。此外，由于每个主体液滴根据其质量偏转，因此偏转光束的空间过滤转化为中性脆弱纳米液滴的尺寸过滤。作为一个例子，我们测量掺杂剂电离概率作为液滴半径的函数，并确定电荷跳跃通过氦矩阵的平均自由程。该技术将实现掺杂和纯纳米液滴的分离以及尺寸相关的光谱研究。
Helium nanodroplets doped with polar molecules are studied by electrostatic deflection. This broadly applicable method allows even polyatomic molecules to attain subkelvin temperatures and nearly full orientation in the field. The resulting intense force from the field gradient strongly deflects even droplets with tens of thousands of atoms, the most massive neutral systems studied by beam “deflectometry.” We use the deflections to extract droplet size distributions. Moreover, since each host droplet deflects according to its mass, spatial filtering of the deflected beam translates into size filtering of neutral fragile nanodroplets. As an example, we measure the dopant ionization probability as a function of droplet radius and determine the mean free path for charge hopping through the helium matrix. The technique will enable separation of doped and neat nanodroplets and size-dependent spectroscopic studies.