Penning ionisation (PI) processes involving pairs of Rydberg alkali-metal atoms, excited to different quantum states and experiencing dipole–dipole interactions, have a wide range of important properties in atomic physics. Within the framework of the semiclassical approximation, we have used both numerical and analytical approaches to examine the Penning autoionisation width dependence on the state quantum numbers in a quasi-molecule formed by the interacting partner atoms. We described the characteristics of optimal quantum numbers that lead to enhanced PI widths for the interacting Rydberg atom pairs of all alkali-metal atoms. The excited states of atoms in these pairs are asymmetric, resulting in a large atomic shell size difference: inspired by Efimov etal (2016 J. Phys. B: At. Mol. Opt. Phys. 49 125302), we call such a pair ‘Tom’ and ‘Jerry’ (for ‘big’ and ‘small’). Compared to symmetric pairs, the optimal asymmetric pairs display a significant (by several orders of magnitude) increase in the PI rate. This property makes PI a relevant source for producing charged particles in cold Rydberg systems that spontaneously evolve into cold plasma. Contrary to hydrogen atoms examined in (Efimov etal 2016 J. Phys. B: At. Mol. Opt. Phys. 49 125302), the difference in quantum defects in alkali-metal atoms results in a strong Penning width dependence on the orbital quantum numbers l of the quasi-molecule. In particular, alkali-metal atoms exhibit two PI channels associated with bound–bound optical transitions showing Δl = 1—individual and closely spaced (doublet-like) configurations of optimal pairs. Furthermore, we demonstrate that the presence of Frster resonances can lead to a notable (up to five times) increase in the PI efficiency.

Penning 电离 (PI) 过程涉及成对的里德堡碱金属原子，激发到不同的量子态并经历偶极-偶极相互作用，在原子物理学中具有广泛的重要特性。在半经典近似的框架内，我们使用数值和分析方法来检查 Penning 自电离宽度对相互作用伙伴原子形成的准分子中状态量子数的依赖性。我们描述了最佳量子数的特征，这些特征导致所有碱金属原子的相互作用的里德堡原子对的 PI​​ 宽度增强。这些对中原子的激发态是不对称的，导致原子壳尺寸差异很大：受 Efimov等人的启发(2016 J. Phys. B: At. Mol. Opt. Phys. 49 125302），我们称这样的一对为“汤姆”和“杰瑞”（代表“大”和“小”）。与对称对相比，最佳非对称对显示出 PI 率的显着（几个数量级）增加。这种特性使 PI 成为在冷里德堡系统中产生带电粒子的相关来源，这些粒子自发演化为冷等离子体。与 (Efimov et al 2016 J. Phys. B: At. Mol. Opt. Phys. 49 125302) 中研究的氢原子相反，碱金属原子中量子缺陷的差异导致对轨道量子数的强烈彭宁宽度依赖性l的准分子。特别是，碱金属原子表现出两个与束缚光学跃迁相关的 PI 通道，显示 Δ l= 1 - 最佳对的单个和紧密间隔（类似双峰）的配置。此外，我们证明 Frster 共振的存在可以导致 PI 效率显着（最多五倍）增加。