Jan-Wilke Henke1,Claus Ropers1,2
Max Planck Institute for Multidisciplinary Sciences1,University of Göttingen2
Jan-Wilke Henke1,Claus Ropers1,2
Max Planck Institute for Multidisciplinary Sciences1,University of Göttingen2
Providing the most detailed views of atomic-scale structure and composition, transmission electron microscopy serves as an indispensable tool for structural biology and materials science. The combination of electron microscopy with pulsed electrical or optical stimuli allows for the study of transient phenomena, involving magnetization dynamics, strain evolution and structural phase transformations. Ultrafast transmission electron microscopy (UTEM) is a pump-probe technique, in which non-equilibrium processes can be tracked with simultaneous femtosecond temporal and nanometer to atomic-scale spatial resolutions.<br/>This talk will cover recent methodical developments and applications in UTEM based on laser-triggered field emitters, including real-space imaging [1] and ultrafast nanobeam diffraction [2] of structural phase transitions. Moreover, the mechanisms involved in free-electron beams interacting with optical fields at photonic structures will be discussed, emphasizing quantum effects. In particular, recent progress in the coupling of electron beams to whispering gallery modes [3] and integrated photonic resonators [4] will be presented. Finally, using event-based electron spectroscopy, the preparation and characterization of electron-photon pair states [5] and Coulomb-correlated electron number states [6] will be discussed.<br/><br/><u>References:</u><br/>[1] "Ultrafast nanoimaging of the order parameter in a structural phase transition”, T. Danz, T. Domröse, C. Ropers, Science <b>371</b>, 6527 (2021).<br/>[2] "Light-induced hexatic state in a layered quantum material", T. Domröse, Th. Danz, and C. Ropers, Nature Materials (in press, 2023),<br/>arXiv:2207.05571 (2022), URL: https://www.nature.com/articles/s41563-023-01600-6<br/>[3] "Controlling free electrons with optical whispering-gallery modes", O. Kfir <i>et al.</i>, Nature <b>582</b>, 46 (2020).<br/>[4] "Integrated photonics enables continuous-beam electron phase modulation", J.-W. Henke <i>et al.</i>, Nature <b>600</b>, 653 (2021).<br/>[5] “Cavity-mediated electron-photon pairs”, A. Feist <i>et al.</i>, Science <b>377</b>, 777 (2022).<br/>[6] "Coulomb-correlated electron number states in a transmission electron microscope beam", R. Haindl <i>et al.</i>, <i>Nat. Phys.</i> (appeared online, 2023). https://doi.org/10.1038/s41567-023-02067-7