Ionization-coherence-enhanced-vibration photoexcitation in nitrogen ions

We develop a vibronic coherence model for multiorbital ionization and excitation of nitrogen molecules, based on an up-to-date concept of coherent ionization into excited states [C. H. Yuen and C. D. Lin, Phys. Rev. A 108, 023123 (2023)2469-992610.1103/PhysRevA.108.023123; Phys. Rev. A 109, 033108 (2024)2469-992610.1103/PhysRevA.109.033108]. Compared to other models, where the coherence of excitation dynamics is described with fewer details, our model predicts larger populations at excited states, in particular, at levels corresponding to the transition wavelengths 391 or 428 nm relevant to air lasing in the atmospheric environment. The dependence of population inversion on the pump wavelength is investigated, showing that ionic coherence in ionization injection enhances the vibronic three-photon transition in the N2 postionization process.