Sympathetic Cooling of Large Molecules in a Cold-Atom Trap

冷原子阱中大分子的交感冷却

基本信息

批准号：
97830361
负责人：
Professor Dr. Hanspeter Helm
金额：
--
依托单位：
Abteilung Attosekunden- und Starkfeldphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2008
资助国家：
德国
起止时间：
2007-12-31 至无数据
项目状态：
未结题

来源：
https://gepris.dfg.de/gepris/projekt/97830361?language=en
关键词：
Sympathetic Cooling Large Molecules Cold

项目摘要

Quantum chemistry and computational chemistry can nowadays determine to a high degree of precision internal energy states of even large molecules. Likewise molecular dynamics methods permit time- and space-resolved views of changes in molecular structure, which may occur following interaction with external force fields. Experimental access to microscopic views of such change is generally limited to ensemble averages in an uncontrolled environment to which the molecule is strongly coupled. The long term goal of our project aims at resolving the stochastic development of internal energy states of a single large molecule (size of 102-103 Dalton) in a controlled environment. We anticipate that the quantum nature of the aggregate can be examined, provided it is kept sufficiently long in an environment at sufficiently low temperature. Under such conditions when hot collisions are absent, weak long-range forces as well as the interaction with the thermal black-body background will control the temporal development of an isolated aggregate. In order to achieve such a goal we will attempt to identify and characterize the structural, dynamic, and coherence properties of an isolated and cold macromolecule, embedded in a trapped cloud of laser-cooled atoms, the trap confining the translational motion of both, refrigerant atoms and the macromolecule. We aim to characterize the spectral quantum signatures, which emerge once the macromolecule reaches sub-Kelvin temperatures. From this study, we hope to identify the stochastic cycles of coupling between molecular degrees of freedom and those of the cold rubidium bath, coupling between translation and the internal degrees of freedom of the molecule, energy-transfer from ground-and excitedstate coolant atoms to the macromolecule at sub-thermal energies, as well as the balance of cooling, heating, and clustering in the combined trap and the role of black-body radiation.This ambitious project entails several subprojects, some of which have by this time been completed (see below 2.3) and some which require ongoing research and support by the proposed project (see below 3.3).

如今，量子化学和计算化学也可以确定高度的精度内部能量，甚至大分子。同样，分子动力学方法允许分子结构变化的时间和空间分辨观点，这可能会在与外力场相互作用后发生。在不受控制的环境中，对这种变化的微观观点的实验访问通常仅限于分子强烈耦合的不受控制的环境中。我们项目的长期目标旨在解决在受控环境中单个大分子（大小为102-103 Dalton）的内部能量状态的随机发展。我们预计可以检查骨料的量子性质，只要在足够低温下的环境中保持足够长的时间。在没有热碰撞的情况下，弱远程力以及与热黑体背景的相互作用将控制孤立聚集体的时间发展。为了实现这样一个目标，我们将尝试识别和表征隔离和冷的大分子的结构，动态和连贯性能，并嵌入了被捕获的激光冷却原子云中，限制了陷阱，限制了两者的翻译运动，冷冻原子和大分子。我们的目的是表征光谱量子特征，一旦大分子达到亚克尔文温度，就会出现。 From this study, we hope to identify the stochastic cycles of coupling between molecular degrees of freedom and those of the cold rubidium bath, coupling between translation and the internal degrees of freedom of the molecule, energy-transfer from ground-and excitedstate coolant atoms to the macromolecule at sub-thermal energies, as well as the balance of cooling, heating, and clustering in the combined trap and the role黑体辐射。这个雄心勃勃的项目需要几个子项目，其中一些已经完成（请参阅下文2.3），有些需要该项目的研究和支持（请参见下文3.3）。