近日，印度塔塔基础研究所的Suvasis Swain及其研究小组与印度拉曼研究所的E. Krishnakumar合作并取得一项新进展。经过不懈努力，他们对与解离电子附着中的量子相干性相关的同位素效应进行了研究。相关研究成果已于2024年4月5日在国际知名学术期刊《物理评论A》上发表。

该研究团队最新报道了在解离电子附着（DEA）过程中观察到的H2同位素HD的量子相干性现象。在同位素效应的研究中，他们发现H^-和D^-在角分布上均呈现出相同的向前向后不对称性。为了解释这一发现，研究人员利用了两个量子路径之间的干涉作用，并指出在此过程中，由不对称质量引起的永久偶极矩并未发挥明显作用。

据悉，解离电子附着（DEA）是分子中原子核自由度与电子自由度之间强耦合的重要过程之一。这种耦合作用有效促进了附着自由电子的动能向化合物分子化学能的转化。近期，研究人员在这一过程中发现了量子相干性，为描述DEA过程提供了全新的维度。此外，原子同位素的质量变化对DEA过程产生深远影响。在DEA中观测到的量子相干现象中，同位素效应是通过干涉解离路径的相位和振幅变化来描述的。

附：英文原文

Title: Quantum coherence in dissociative electron attachment: Isotope effect

Author: Suvasis Swain, Akshay Kumar, E. Krishnakumar, Vaibhav S. Prabhudesai

Issue&Volume: 2024/04/05

Abstract: Dissociative electron attachment (DEA) is one of the processes that shows a strong coupling between the nuclear and electronic degrees of freedom in a molecule. This coupling results in an efficient transformation of the kinetic energy of attaching free electrons into the chemical energy of the compound molecule. A recent discovery of quantum coherence in this process has opened a different dimension in its description. On the other hand, the mass variation in isotopes of the constituent atoms has a profound effect on DEA. In quantum coherence observed in DEA, the isotope effect depicts itself in terms of change in the phase and the amplitude of the interfering dissociation paths. Here, we report the quantum coherence observed in DEA to HD, an isotopolog of H₂. In this isotopolog, both H^- and D^- show identical forward-backward asymmetry in the angular distribution. We explain these findings using the interference between two quantum paths, with the permanent dipole moment due to asymmetric mass playing no role in the process.

DOI: 10.1103/PhysRevA.109.042805

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.042805