近日，吉林大学丁大军团队实现了钠原子双光子共振奥特勒-汤斯分裂的直接观察。这一研究成果发表在2025年6月2日出版的《物理评论A》杂志上。

钠原子中的双光子共振3??−4??? 利用光电子动量成像技术研究了强耦合状态下的跃迁。电离电子的动能映射出了修饰态的本征能量，并表现为Autler-Townes（AT）分裂，由于双光子性质，这与激光强度成正比。光电子角分布的部分波分析揭示了修饰态的相对相移，这与阿秒电离时间延迟有关。AT分裂产生的两个电子波包之间的相移归因于库仑相和量子缺陷相的结合。

附：英文原文

Title: Direct observation of two-photon-resonance Autler-Townes splitting of atomic sodium

Author: Wankai Li, Yixuan Wang, Xing Li, Tao Yang, Dongdong Zhang, Dajun Ding

Issue&Volume: 2025/06/02

Abstract: A two-photon resonance in the sodium atom 3s4s transition is investigated in the strong coupling regime with photoelectron momentum imaging techniques. The kinetic energies of the ionized electron map out the eigenenergies of the dressed states and emerge as the Autler-Townes (AT) splitting, which is proportional to the laser intensity due to the two-photon nature. The partial wave analysis of the angular distribution of the photoelectrons reveals the relative phase shift from dressed states which is related to the attosecond ionization time delays. The phase shift between the two electron wave packets produced from AT splitting are attributed to the combination of the Coulomb phase and the quantum defect phase.

DOI: 10.1103/PhysRevA.111.063102

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.063102