题 目：Ultrafast imaging and control of molecular dynamics
报告人：李 铮 北京大学物理学院
时 间：2025年04月11日（星期五) 上午10：30
地 点：虎溪校区理科楼物理学院 LE201
邀请人：王锐
报告摘要：The Jahn-Teller effect is a fundamental mechanism of spontaneous symmetry breaking in molecular and solid state systems, and has far-reaching consequences in many fields. Up to now, to directly image the onset of Jahn-Teller symmetry breaking remains unreached. Here we employ ultrafast ion-coincidence Coulomb explosion imaging with sub-10 fs resolution and unambiguously image the ultrafast dynamics of Jahn-Teller deformations of CH4+ cation in symmetry space. It is unraveled that the Jahn-Teller deformation from C3v to C2v geometries takes a characteristic time of 20+/-7 fs for this system. Classical and quantum molecular dynamics simulations agree well with the measurement, and reveal dynamics for the build-up of the C2v structure involving complex revival process of multiple vibrational pathways of the CH4+ cation.
李铮，北大物理学院研究员，助理教授。主要从事第一性原理原子分子结构理论，分子动力学，自由电子激光，和光与物质相互作用领域的理论研究，着重于研究与自由电子激光相关的理论，在Science, Phys. Rev. Lett., Nature Commun., J. Am. Chem. Soc., Sci. Adv.等杂志发表研究论文七十余篇。