华中科技大学陆培祥团队近日研究了高次谐波产生的相空间高斯量子系综。相关论文发表在2025年5月20日出版的《物理评论A》杂志上。

研究组提出了一种相空间高斯量子系综来描述高次谐波的产生过程。该模型考虑了波粒二象性和不确定性原理。它将从头计算与半经典分析联系起来，使人们能够区分不同的通道并揭示潜在的电子动力学。课题组研究了短、长和多重散射轨道谐波的电离和复合时间。该模型还提供了研究位置动量特性的方法。 

结果表明，电子在隧道出口处具有非零的初始速度，揭示了非绝热效应。研究组通过解释双色干涉实验中的可观测值来证明该分析的有效性。正交极化场中任何双色延迟的非零横向谐波信号都可以用量子系综的离域分布来解释。该模型可以指导半经典分析，并为高次谐波光谱提供基准。

附：英文原文

Title: Phase-space Gaussian quantum ensemble for high-order harmonic generation

Author: Sen Qiao, Liang Li, Hubin Cui, Shiyu Zeng, Shiqi Liang, Pengfei Lan, Peixiang Lu

Issue&Volume: 2025/05/20

Abstract: We propose a phase-space Gaussian quantum ensemble to depict the high-order harmonic generation process. Our model takes the wave-particle duality and the uncertainty principle into account. It bridges the ab initio calculation with the semiclassical analysis, enabling us to distinguish different channels and reveal the underlying electron dynamics. We investigate the ionization and recombination time of the short, long, and multi-rescattering trajectory harmonics. Our model also provides access to investigate the position-momentum properties. Results demonstrate that the electron has a nonzero initial velocity at the tunnel exit, revealing the nonadiabatic effect. We prove the validity of our analysis by interpreting the observables in the two-color interference experiments. The nonzero transverse harmonic signal for any two-color delay in the orthogonally polarized fields can be explained by the delocalized distribution of the quantum ensemble. Our model can guide the semiclassical analysis and provide a benchmark for high-order harmonic spectroscopy.

DOI: 10.1103/PhysRevA.111.053114

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.053114