Chadwick Helen, Somers Mark F, Stewart Aisling C, Alkoby Yosef, Carter Thomas J D, Butkovicova Dagmar, Alexandrowicz Gil
Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, SA2 8PP, UK.
Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands.
Nat Commun. 2022 Apr 28;13(1):2287. doi: 10.1038/s41467-022-29830-3.
Rotational motion lies at the heart of intermolecular, molecule-surface chemistry and cold molecule science, motivating the development of methods to excite and de-excite rotations. Existing schemes involve perturbing the molecules with photons or electrons which supply or remove energy comparable to the rotational level spacing. Here, we study the possibility of de-exciting the molecular rotation of a D molecule, from J = 2 to the non-rotating J = 0 state, without using an energy-matched perturbation. We show that passing the beam through a 1 m long magnetic field, which splits the rotational projection states by only 10eV, can change the probability that a molecule-surface collision will stop a molecule from rotating and lose rotational energy which is 9 orders larger than that of the magnetic manipulation. Calculations confirm that different rotational orientations have different de-excitation probabilities but underestimate rotational flips (∆m[Formula: see text]0), highlighting the importance of the results as a sensitive benchmark for further developing theoretical models of molecule-surface interactions.
旋转运动是分子间、分子与表面化学以及冷分子科学的核心，推动了激发和去激发旋转方法的发展。现有方案涉及用光子或电子扰动分子，这些光子或电子提供或去除与旋转能级间距相当的能量。在这里，我们研究了在不使用能量匹配扰动的情况下，将D分子的分子旋转从J = 2去激发到非旋转的J = 0态的可能性。我们表明，让光束穿过一个仅将旋转投影态分裂10电子伏特的1米长磁场，可以改变分子与表面碰撞使分子停止旋转并损失旋转能量的概率，这一概率比磁操纵的概率大9个数量级。计算证实不同的旋转取向具有不同的去激发概率，但低估了旋转翻转（∆m≠0），突出了这些结果作为进一步发展分子与表面相互作用理论模型的敏感基准的重要性。
