We are glad to present
Claus Ropers
Max Planck Institute for Multidisciplinary Sciences
Monday, 8th May 2023 at 18:00
Freihaus Hörsaal 3 at TU Wien (Wiedner Hauptstraße 8, 1040 Vienna, 2. OG)
Ultrafast Electron Microscopy
Providing the most detailed views of atomic-scale structure and composition, Transmission Electron Microscopy (TEM) 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, which tracks non-equilibrium processes with simultaneous femtosecond temporal and nanometer to atomic-scale spatial resolutions. This talk will introduce UTEM based on laser-triggered field emitters, and will provide application examples in the real-space imaging of structural phase transitions [1] and magnetization dynamics [2]. Moreover, the mechanisms involved in free-electron beams interacting with optical fields at photonic structures will be discussed, emphasizing quantum effects. In particular, I will present recent progress in the coupling of electron beams to whispering gallery modes [3] and integrated photonic resonators [4]. Finally, using coincidence spectroscopy, the preparation and characterization of electron-photon pair states [5] and Coulomb-correlated few-electron states is demonstrated [6].
References: [1] “Ultrafast nanoimaging of the order parameter in a structural phase transition”, Th. Danz, T. Domröse, C. Ropers, Science 371, 6527 (2022) [2] “Pinning and gyration dynamics of magnetic vortices revealed by correlative Lorentz and bright-field imaging”, M. Möller et al., Phys. Rev. Research 4, 013027 (2022). [3] “Controlling free electrons with optical whispering-gallery modes”, O. Kfir et al., Nature 582, 46 (2020). [4] “Integrated photonics enables continuous-beam electron phase modulation”, J.-W. Henke et al., Nature 600, 653 (2021). [5] “Cavity-mediated electron-photon pairs”, A. Feist et al., Science 377, 777 (2022). [6] “Coulomb-correlated electron number states in a transmission electron microscope beam”, R. Haindl et al., arXiv:2207.05571 (2022).
Host: Philipp Haslinger (TU Wien)
For further information and a Zoom link please visit: https://vcq.quantum.at/colloquium-ss-23/
Program
18:00 – Student Talk by Ksenija Simonovic (UNIVIE) “Exploring molecular properties using far-field matter-wave diffraction”
18:15 – VCQ Colloquium talk by Prof. Ropers
After the talk drinks & snacks on the roof-top terrace (Freihaus, Tower A, 9. OG )
Picture Credit © Swen Pförtner
