A spectral-dip fingerprint of quantum path interference in high harmonic generation

作者：Zheng Shu, Yue Wang, Yin Zhao, Jing Ma, Bodun Liu, Xiaolei Hao, Ri Ma, Jing Chen · 发表于：Journal of Physics B Atomic Molecular and Optical Physics · 年份：2026 · DOI：10.1088/1361-6455/ae73ca · 被引用次数：1 · 研究领域：Laser-Matter Interactions and Applications、Spectroscopy and Quantum Chemical Studies、Laser-Plasma Interactions and Diagnostics

Abstract High harmonic spectroscopy, as a self-referenced attosecond technique, is widely used to probe electronic structure and dynamics in both atoms and polyatomic molecules. In this study, we theoretically and experimentally investigate the high-harmonic spectra of argon at various laser intensities, revealing a distinctive spectral minimum in the near cutoff region. This feature, attributed to the destructive interference between short and long electron trajectories, serves as a spectroscopic fingerprint of quantum path interference. By analyzing the relative contributions and phases of these quantum paths, we demonstrate that the spectral minimum represents a new modulation pattern of quantum path interference with a period of 0.2 × 10 14 W cm − 2 . This provides new insights into the dynamics of electron trajectories and offers a potential diagnostic tool for observing and controlling ultrafast electronic processes in laser-matter interactions.