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Majed Chergui | Ècole Polytechnique | Lausanne, Switzerland

“Time-resolved optical and X-ray spectroscopies of biological dynamics”

Scientific Talks, Session VI | Tuesday, September 13 | 13:50 – 14:20

The past ten years have witnessed a revolution in science with the advent of new ultrafast optical and X-ray domain methodologies enabled by new instrumentation, such as X-ray free electron lasers (XFEL) and table-top HHG sources of Extreme UV pulses radiation. In this presentation, I will focus on developments in deep-UV (sub-300 nm) to X-ray spectroscopies. I will present some results of 2D deep-UV studies of biological systems, revealing hitherto unknown electron transfer processes, [1,2] and then proceed to presenting recent ultrafast deep-UV Circular dichroism studies of molecular systems, [3–5] which promise applications for biological systems. I will then present the first results on the X-ray helical dichroism of molecular systems, [6] and move onto recent developments in ultrafast non-linear X-ray science, focusing on hard X-ray transient grating spectroscopy, [7,8] as well as subsequent developments.
[1] C. Consani, G. Aubock, F. van Mourik, and M. Chergui, Ultrafast Tryptophan-to-Haem Electron Transfer in Myoglobins Revealed by UV 2D Spectroscopy, Science 339, 1586 (2013).
[2] R. Monni, A. Al Haddad, F. van Mourik, G. Auböck, and M. Chergui, Tryptophan-to-Heme Electron Transfer in Ferrous Myoglobins, Proceedings of the National Academy of Sciences 112, 18 (2015).
[3] M. Oppermann, B. Bauer, T. Rossi, F. Zinna, J. Helbing, J. Lacour, and M. Chergui, Ultrafast Broadband Circular Dichroism in the Deep Ultraviolet, Optica, OPTICA 6, 56 (2019).
[4] M. Oppermann, J. Spekowius, B. Bauer, R. Pfister, M. Chergui, and J. Helbing, Broad-Band Ultraviolet CD Spectroscopy of Ultrafast Peptide Backbone Conformational Dynamics, J. Phys. Chem. Lett. 10, 11 (2019).
[5] M. Oppermann, F. Zinna, J. Lacour, and M. Chergui, Chiral Control of Spin-Crossover Dynamics in Fe(II) Complexes, Nat. Chem. (2022).
[6] J. R. Rouxel et al., Hard X-Ray Helical Dichroism of Disordered Molecular Media, Nat. Photon. 16, 8 (2022).
[7] C. Svetina et al., Towards X-Ray Transient Grating Spectroscopy, Opt. Lett., OL 44, 574 (2019).
[8] J. R. Rouxel et al., Hard X-Ray Transient Grating Spectroscopy on Bismuth Germanate, Nat. Photon. 15, 499 (2021).