Jiang Wenyu, Roantree Luke, Han Lulu, Ji Jiabao, Xu Yidan, Zuo Zitan, Wörner Hans Jakob, Ueda Kiyoshi, Brown Andrew C, van der Hart Hugo W, Gong Xiaochun, Wu Jian
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, China.
Nat Commun. 2025 Jan 3;16(1):381. doi: 10.1038/s41467-024-55247-1.
Partial wave analysis is key to interpretation of the photoionization of atoms and molecules on the attosecond timescale. Here we propose a heterodyne analysis approach, based on the delay-resolved anisotropy parameters to reveal the role played by high-order partial waves during photoionization. This extends the Reconstruction of Attosecond Beating By Interference of Two-photon Transitions technique into the few-photon regime. We demonstrate that even for moderate ( ~ 1TW/cm) intensities, near-infrared-assisted photoionization of helium through Rydberg states results in a tiny contribution from the g wave, which has a significant impact on the photoelectron angular distributions via interference with the s- and d-waves. This modulation also causes a substantial deviation in the angular distribution of the recovered spectral phase shift. Our analysis provides an efficient method to resolve isolated partial wave contributions beyond the perturbative regime, and paves the way towards understanding resonance-enhancement of partial waves.
分波分析是在阿秒时间尺度上解释原子和分子光电离的关键。在此，我们提出一种外差分析方法，基于延迟分辨各向异性参数来揭示高阶分波在光电离过程中所起的作用。这将双光子跃迁干涉重建阿秒脉冲技术扩展到了少光子领域。我们证明，即使对于中等强度（~1TW/cm），通过里德堡态实现的氦原子近红外辅助光电离会导致g波的微小贡献，该贡献通过与s波和d波的干涉对光电子角分布产生显著影响。这种调制还会导致恢复的光谱相移角分布出现实质性偏差。我们的分析提供了一种有效的方法来解析微扰区域之外孤立的分波贡献，并为理解分波的共振增强铺平了道路。
