de Jongh Tim, Shuai Quan, Abma Grite L, Kuijpers Stach, Besemer Matthieu, van der Avoird Ad, Groenenboom Gerrit C, van de Meerakker Sebastiaan Y T
Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.
Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collége de France, Paris, France.
Nat Chem. 2022 May;14(5):538-544. doi: 10.1038/s41557-022-00896-2. Epub 2022 Feb 24.
One of the most important parameters in a collision is the 'miss distance' or impact parameter, which in quantum mechanics is described by quantized partial waves. Usually, the collision outcome is the result of unavoidable averaging over many partial waves. Here we present a study of low-energy NO-He collisions that enables us to probe how individual partial waves evolve during the collision. By tuning the collision energies to scattering resonances between 0.4 and 6 cm, the initial conditions are characterized by a limited set of partial waves. By preparing NO in a rotationally excited state before the collision and by studying rotational de-excitation collisions, we were able to add one quantum of angular momentum to the system and trace how it evolves. Distinct fingerprints in the differential cross-sections yield a comprehensive picture of the partial wave dynamics during the scattering process. Exploiting the principle of detailed balance, we show that rotational de-excitation collisions probe time-reversed excitation processes with superior energy and angular resolution.
碰撞中最重要的参数之一是“错过距离”或碰撞参数，在量子力学中它由量子化的分波来描述。通常，碰撞结果是对许多分波进行不可避免的平均的结果。在此，我们展示了一项关于低能一氧化氮-氦碰撞的研究，该研究使我们能够探究各个分波在碰撞过程中是如何演化的。通过将碰撞能量调谐到0.4至6厘米之间的散射共振，初始条件由一组有限的分波来表征。通过在碰撞前将一氧化氮制备到转动激发态，并研究转动退激发碰撞，我们能够向系统添加一个角动量量子并追踪其演化过程。微分截面中的独特特征给出了散射过程中分波动力学的全面图景。利用细致平衡原理，我们表明转动退激发碰撞能够以卓越的能量和角分辨率探测时间反演的激发过程。
