近日，日本京都大学的Masato Senami及其研究团队取得一项新进展。经过不懈努力，他们证实电子激发能够增强分子电子手性。相关研究成果已于2024年11月12日在国际知名学术期刊《物理评论A》上发表。
先前的研究预测，在手性分子中，对映体之间的宇称破缺能量差（PVED）以及分子电子手性（MEC，即整个分子上电子手性密度的积分值），在电离或电子激发时会得到增强。在该研究之前的研究论文中已证实了电子激发会增强PVED，本研究则进一步证实了电子激发会增强H2Te2和H2Se2的MEC。
如果基态中最高占据分子轨道对PVED的贡献占主导地位，那么第一激发态的PVED就可以由最高占据分子轨道的贡献来解释。本文检验了这一解释是否也适用于MEC。此外，研究人员还报道了MEC并非简单由各原子贡献相加而成，不同原子的原子轨道之间的叠加混合起着重要作用。
附：英文原文
Title: Enhancement of the molecular electron chirality by electronic excitation
Author: Naoya Kuroda, Masato Senami
Issue&Volume: 2024/11/12
Abstract: Previously, it was predicted that the parity-violating energy difference (PVED) between enantiomers and the molecular electron chirality (MEC), which is the integrated value of the electron chirality density over the entire molecule, are enhanced for ionization or electronic excitation. Following the confirmation of the enhancement of the PVED by electronic excitation in our previous papers, the present work confirms that electronic excitation enhances the MEC for H2Te2 and H2Se2. The PVED in the first excited state is explained by the contribution from the highest occupied molecular orbital if the PVED contribution from the highest occupied molecular orbital in the ground state dominates over any other contributions. In this paper, it is checked whether this explanation can also be applicable to the MEC. It is also reported that the MEC is not the simple sum of contributions from each atom and the mixing by the superposition between atomic orbitals of different atoms is important.
DOI: 10.1103/PhysRevA.110.052211
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.05221