Prof. Dr. Xijie Wang 

„The research in my group is to explore Mega-electron-volt (MeV) ultrafast electron diffraction and imaging (MeV-UED/MeV-UEM) for ultrafast material, chemical and biological science.  We pioneered the idea using MeV electrons for MeV-UED and MeV-UEM ^1-2. MeV-UED became a new frontier in ultrafast science due to its capability of following dynamics on femtoseconds scale with the high spatial resolution and sensitivity ^3-4. Furthermore, MeV electrons experience less multiple-scattering, and possess “real” flat Ewald-sphere; MeV ultrafast electron diffraction (MeV-UED) is an ideal tool to explore both structure and dynamics using total scattering technique.   MeV-UED had broad and transformative impact on ultrafast science, such as the first 2-D materials ultrafast structure dynamics ⁵, break the long-standing puzzle of efficiency degradation of quantum dots ⁶, light-induced transient states of quantum materials ^7-8, the first direct imaging of fundamental chemical processes ^9-10 and hydrogen bond dynamics in liquid water ¹¹. Recently, we have demonstrated the first operando experiment in ultrafast ¹², the successful ultrafast visualization of incipient plasticity in dynamically compressed matter ¹³, the observation of Einstein-de Haas effect in an antiferromagnetic material ¹⁴ and capturing the generation and structural transformation of molecular ions ¹⁵.  We propose to develop new generation MeV ultrafast scattering instrument in Ruhr aera to address grand challenges in material, chemical and biological science, such as imaging proton transfer and disentangling electron-nuclear coupling.“ 

¹ X.J. Wang et al, Phys. Rev. E , 54, No.4, R3121 -3124 (1996)
² X.J. Wang et al, Proceedings of the 2003 Particle Accelerator Conference, 2003, pp. 420-422 Vol.1, doi: 10.1109/PAC.2003.1288940
³ P. Zhu et al, New Journal of Physics 17 (6), 063004 (2014)
⁴ S. Weathersby et al, Rev. Sci. Instrum. 2015, 86, 073702−073707 
⁵ E. M. Mannebach et al, Nano Lett. 15, 6889 (2015) 
⁶ Burak Guzelturk et al., Nat Commun 12, 1860 (2021) 
⁷ E. J. Sie et al, Nature 565,61–66(2019)  
⁸ A. Kogar et al, Nat. Phys.16, 159 (2019) 
⁹ J. Yang et al, Science 361, 64 (2018) 
¹⁰ T. J. A. Wolf et al, Nat. Chem. (2019)
¹¹ J. Yang et al., Nature 596, 531–535 (2021) 
¹² J. A. Sood et al, Science 373, 352 (2021)
¹³ M. Mo et al, Nat. Commun. 13, (2022)
¹⁴ A. Zong  et al., Nature 620, 988–993 (2023)
¹⁵ J. Heo et al, Nature 625, pages 710–714 (2024)