Dynamics of Ions in Superfluid Helium Nanodroplets

在这个由化学学部实验物理化学项目资助的奖项中，弗吉尼亚大学的Kevin K. Lehmann教授和他的博士后和研究生同事将使用液氦纳米液滴作为独特的实验室来研究分子在受限量子流体中的行为方式。Lehmann和他的团队计划研究选定大小的氦滴中离子的行为，以寻找新的流体效应（漩涡环或旋转）的存在。此外，Lehmann和他的团队将使用纳米液滴作为量热计——通过检测氦原子的蒸发来测量放热过程的能量学。其他实验计划研究这些量子流体中具有受激旋转、振动和自旋自由度的分子的弛豫动力学。氦纳米液滴是一种不寻常的量子环境，其行为仍然知之甚少。这些研究的结果将为对这些系统建模感兴趣的理论家提供关键的基准。量热法的工作是至关重要的，因为它允许直接测定热化学信息——一次测定一个分子。参与该项目的学生和博士后将在化学和凝聚态物理的界面上接受广泛的跨学科培训。

In this award, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Prof. Kevin K. Lehmann of the University of Virginia and his postdoctoral and graduate student colleagues will use liquid helium nanodroplets as unique laboratories for studying the ways in which molecules behave in confined quantum fluids. Lehmann and his group plan on studying the behavior of ions in size-selected helium droplets to search for the presence of novel fluid effects (vortex rings or rotons). In addition, Lehmann and his group will use the nanodroplet as a calorimeter -- measuring the energetics of exothermic processes by detecting the evaporation of helium atoms. Other experiments plan on studying the poorly-understood relaxation dynamics of molecules with excited rotational, vibrational and spin degrees of freedom in these quantum fluids.Helium nanodroplets are an unusual quantum environment whose behavior is still poorly understood. The results of these investigations will provide crucial benchmarks for theorists interested in modeling these systems. The work in calorimetry is of fundamental importance since it allows thermochemical information to be determined directly -- a molecule at a time. The students and postdoctoral fellows working on this project will be provided with broad interdisciplinary training at the interface of chemistry and condensed matter physics.