Speaker
Description
Conical intersections (CIs) play a vital role in processes such as the event of vision and DNA damage from sunlight. A CI appears in a molecule when electronic and nuclear motions are strongly coupled, and it acts as a funnel that guides a molecule from one electronic state to another. Substantial efforts have been made toward understanding such non-adiabatic phenomena. X-ray Raman techniques have been proposed in the past to investigate the presence of a CI in molecules. We propose a two-dimensional Raman probe scheme that uses a visible/infrared pulse and an ultra-short X-ray Raman probe pulse [1]. The visible/infrared pulse interaction creates a coherent superposition of electronic states in the molecule. Probing the coherent superposition using ultra-short X-ray pulses allows visualizing the dynamic energy separation between electronic states throughout the photochemical process. The lifetime of the coherent superposition created using the infrared pulse can be read directly from two-dimensional Raman spectra. Therefore, the method aids in observing multiple indicators of a conical intersection and may allow for a more detailed study of non-adiabatic dynamics in molecules.
[1] Deependra Jadoun and Markus Kowalewski. Tracking Conical Intersections with Nonlinear X-ray Raman Spectroscopy. Ultrafast Sci., 2022:0003, 2022.
