Deceleration and cold collisions for neutral molecules and Rydberg atoms

1.分子的平移控制在这一研究项目中，研究人员通过计算证明，可以使用施加时变电场的斯塔克减速器，将冷束中的分子在13mK时减速至静止。研究结果已作为特邀报告提交给第七届亚洲原子和分子物理国际研讨会(印度金奈)，目前正在进行评审工作。纳米碳网的声子色散曲线分子的减速和平移冷却可能会对研究束流和表面分子的碰撞产生重大影响。在这方面，研究人员建立了聚并苯的声子色散曲线，它可以作为高取向热解石墨(HOPG)表面散射实验中的声子色散曲线的模型。这篇论文已经发表在《化学物理杂志》上，使材料科学的读者能够理解。用于多排碳纳米带的那些也已经被阐明，并将很快被出版。重点在于，这些结果是基于对多环芳烃的严格光谱知识。分子的取向控制拉曼强度反映了分子的诱导极化率。在全局运动中，取代苯类似物的拉曼散射活性很大。计算表明，涉及σ-π轨道混合的环链相互作用起到了关键作用。当引入卤素原子或两个环的桥结构时，拉曼强度被计算得非常大。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.