Seeing Atoms and Electrons in Space and Time

The fundamental reason behind almost any light-matter interaction are atomic and electronic motion in space and time. In order to provide a movie-like access to such dynamics, we unify electron microscopy with attosecond and femtosecond laser technology. In this way, we combine the awesome spatial resolution of modern electron beams with the spectacular time resolution that is offered by the cycle period of light [1]. Selected results will be reported on the electric fields within metamaterials [2-3], the Einstein-de-Haas effect on atomic dimensions [4], the reaction path of phase transitions [5] and the formation of free-electron qubit states [6]. Many breakthroughs in science and technology have been achieved by disruptive imaging techniques, and our 4D electron microscopy may play this role for light-matter interaction on atomic dimensions.

[1] C. Kealhofer, W. Schneider, D. Ehberger, A. Ryabov, F. Krausz, P. Baum, “All-optical control and metrology of electron pulses”, Science 352, 429 (2016).
[2] A. Ryabov and P. Baum, “Electron microscopy of electromagnetic waveforms”, Science 353, 374 (2016).
[3] K. J. Mohler, D. Ehberger, I. Gronwald, C. Lange, R. Huber, P. Baum, „Ultrafast electron diffraction from nanophotonic waveforms via dynamical Aharonov-Bohm phases“, Science Advances (2020).
[4] S. R. Tauchert, M. Volkov, D. Ehberger, D. Kazenwadel, M. Evers, H. Lange, A. Donges, A. Book, W. Kreuzpaintner, U. Nowak, P. Baum, “Polarized phonons carry angular momentum in femtosecond demagnetization”, Nature 602, 73 (2022).
[5] P. Baum, Ding-Shyue Yang, A. H. Zewail, “4D Visualization of Transitional Structures in Phase Transformations by Electron Diffraction”, Science 318, 788 (2007).
[6] M. Tsarev, A. Ryabov, P. Baum, “Free-Electron Qubits and Maximum-Contrast Attosecond Pulses via Temporal Talbot Revivals”, Phys. Rev. Res. 3, 043033 (2021).