近日，中国科学院上海高等研究院的江玉海及其研究团队取得一项新进展。经过不懈努力，他们利用库仑重塑太赫兹辐射探测电子运动和核心势。相关研究成果已于2024年7月11日在国际知名学术期刊《物理评论A》上发表。

电子的运动性质以及原子和分子的结构信息被编码为强场感应辐射，其波长范围从太赫兹（THz）延伸至极紫外区域。该研究团队通过实验测量了双色激光场中太赫兹产率与椭圆率以及脉冲间相位延迟的关系，并通过轨迹计算建立了太赫兹发射与光电子波包运动之间的关联。他们发现，当激光场的偏振状态从椭圆偏振调整为线偏振时，光电子与母核之间的相互作用会从软碰撞转变为再碰撞，这一转变可以在太赫兹辐射中得以体现。

软碰撞能更有效地通过太赫兹极化来重建电子动力学，这使得研究人员能够在椭圆偏振激光场中构建出反映库仑重塑太赫兹辐射产生介质的有效核心势。这项研究工作为他们设计创新的全光太赫兹测量技术，以探索电子和结构动力学，提供了可能。

附：英文原文

Title: Probing electronic motion and core potential by Coulomb-reshaped terahertz radiation

Author: Ziyang Gan, Kaixuan Zhang, Yuan Gao, Ahai Chen, Yizhu Zhang, Tian-Min Yan, Thomas Pfeifer, Yuhai Jiang

Issue&Volume: 2024/07/11

Abstract: The nature of electronic motion and structural information of atoms and molecules is encoded into strong-field-induced radiation ranging from terahertz (THz) to extreme ultraviolet wavelength. The dependence of THz yields in bichromatic laser fields on ellipticity and interpulse phase delay was experimentally measured, and the trajectory calculations establish the link between the THz emission and the motion of the photoelectron wave packet. The interaction between the photoelectron and the parent core transforms from a soft collision to recollision as the laser field is tuned from elliptical to linear polarization, which can be reflected in THz emission. The soft collision is found to be more effective in reconstructing electron dynamics through THz polarization, which enables us to construct the effective core potential of the generating medium with the Coulomb-reshaped THz radiation in an elliptically polarized laser field. Our work enables us to design innovative all-optical THz measurements of electronic and structural dynamics.

DOI: 10.1103/PhysRevA.110.013110

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.013110