Ultrafast transfer and transient entrapment of photoexcited Mg electron in Mg@C60

Ultrafast relaxation of photoexcited superfluid He nanodroplets

The relaxation of photoexcited nanosystems is a fundamental process of light-matter interaction. Depending on the couplings of the internal degrees of freedom, relaxation can be ultrafast, converting electronic energy in a few fs, or slow, if the energy is trapped in a metastable state that decouples from its environment. Here, helium nanodroplets are resonantly excited by femtosecond extreme-ultraviolet (XUV) pulses from a seeded free-electron laser. Despite their superfluid nature, we find that helium nanodroplets in the lowest electronically excited states undergo ultrafast relaxation. By c…

Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy

Conical intersections between electronic states often dictate the chemistry of photoexcited molecules. Recently developed sources of ultrashort extreme ultraviolet (XUV) pulses tuned to element-specific transitions in molecules allow for the unambiguous detection of electronic state-switching at a conical intersection. Here, the fragmentation of photoexcited iso-propyl iodide and tert-butyl iodide molecules (i-C$_{3}$H$_{7}$I and t-C$_{4}$H$_{9}$I) through a conical intersection between $^{3}$Q$_{0}$/$^{1}$Q$_{1}$ spin-orbit states is revealed by ultrafast XUV transient absorption measuring io…

光激发C60中的超快非绝热电子动力学：DFT交换关联泛函之间的比较研究

Ultrafast nonadiabatic electron dynamics in photoexcited C60: A comparative study among DFT exchange-correlation functionals

本文结合非绝热分子模拟与含时DFT方法，研究了C60分子的非辐射电子弛豫动力学，通过比较PBE、PBE0和B3LYP泛函，揭示了超快布居数动力学对未占据能带结构的普遍依赖性，为光谱探测和计算方法优化提供了依据。

Emergence and relaxation of an e-h quantum liquid phase in photoexcited MoS2 nanoparticles at room temperature

Low-dimensional transition metal dichalcogenide, TMDC, materials are heralding a new era in optoelectronics and valleytronics owing to their unique properties. Photo-induced dynamics in these systems has mostly been studied from the perspective of individual quasi-particles, including excitons, bi-excitons or, even, trions. Their formation, evolution and decay. The role of multi-body and exciton dynamics, the associated collective behaviour, condensation and inter-excitonic interactions remain intriguing and seek attention, especially in room-temperature scenarios which are relevant for device…

利用超快电子衍射的电荷对成像探测价电子和氢动力学

Probing valence electron and hydrogen dynamics using charge-pair imaging with ultrafast electron diffraction

本研究利用 MeV 超快电子衍射和电荷对分布函数分析，实现了氨光解离过程中价电子与氢关联运动的实空间时间分辨追踪，为分子量子动力学研究开辟了新途径。