Speaker: Yuki Kobayashi, LBNL
Program Description:
Ultrafast XUV/x-ray light sources have emerged as a new tool for real-time observation of chemical dynamics, an ultimate goal of physical chemistry. With the unprecedented time resolution and the unique accessibility to atom-specific core orbitals, the evolution of photoexcited molecules can directly be mapped in great detail. Here, we present attosecond transient absorption experiments on (i) multidimensional coherent processes and (ii) curve-crossing dynamics in small molecular systems. Simultaneous characterization of electronic/vibrational coherences is achieved and evidences of implications of rotational motions are also obtained. Decoherence and recoherence of electronic motion are demonstrated experimentally for the first time. Core-level absorption disentangles degenerate electronic states at an avoided crossing and successfully captures the switching of electronic character. The results show great promise of ultrafast XUV/x-ray light sources in revealing the fast and complex electronic-nuclear dynamics.
