Deceleration and cold collisions for neutral molecules and Rydberg atoms

1. 分子的平移控制在这个研究项目中，研究人员通过计算证明，使用施加时变电场的斯塔克减速机，可以将冷束中的分子减速到13 mK时静止不动。研究结果已在印度金奈举行的第七届亚洲原子与分子物理国际研讨会上作为特邀报告发表，论文目前正在审稿中。纳米碳网络的声子色散曲线分子的减速和平移冷却对研究分子在束和表面的碰撞具有重要的影响。在这方面，研究人员建立了多烯的声子色散曲线，该曲线可以作为高取向热解石墨（HOPG）表面散射实验的模型。这篇论文发表在《化学物理杂志》上，让材料科学的读者能够理解。对多行碳纳米带的结构也进行了阐述，并将于近期发表。重点是这些结果是建立在严格的多环芳烃光谱知识的基础上的。分子的取向控制拉曼强度反映了分子的诱导极化率。取代苯类似物在全局运动时具有较大的拉曼散射活性。σ-π轨道混合的环链相互作用已被计算为起关键作用。当引入卤素原子或两个环的桥结构时，计算出的拉曼强度非常大。这一事实有力地支持了上述机制。

1. Translational control of moleculesIn this research project the investigators have demonstrated by calculations that molecules in a cold beam can be decelerated to standstill at 13 mK using a Stark decelerator which applies time-varying electric fields. The results have been presented in the 7th Asian International Seminar on Atomic and Molecular Physics (Chennai, India) as an invited talk, and the proceeding paper is now under referee processes.2. Phonon dispersion curves of nanosize carbon networksDeceleration and translational cooling of molecules could make a significant impact on research area studying collisions of the molecules in the beam and surfaces. In this respect the investigators has established the phonon dispersion curves of polyacenes, which can act as a model for those of highly oriented pyrolytic graphite (HOPG) in surface scattering experiments. The paper has been published in the Journal of Chemical Physics, enabling readers in material sciences to understand. Those for multirow carbon nanoribbons have also been elucidated, and will be published to a good shortly. The point is that the results are based on the rigorous spectroscopic knowledge on polycyclic aromatic hydrocarbons.3. Orientation control of moleculesThe Raman intensity reflects the induced polarizability in molecules. Large Raman scattering activities have been found for substituted benzene analogues upon global motion. The ring-chain interactions involving σ-π orbital mixing have been calculated to play a key role. When halogen atoms or the bridge structures of two rings are introduced, the Raman intensity have been calculated to be significantly large. This fact supports the above mechanism strongly.