Seminars

European XFEL Science Seminar | Probing molecular electronic and nuclear dynamics in isolated molecules

by Markus Guehr (EXP-Quantum, Postdam Universitaet)

Europe/Berlin
E1.173 European XFEL (European XFEL)

E1.173 European XFEL

European XFEL

Description
Molecules selectively transform light energy into other forms of energy like heat, electricity, or chemical energy with high quantum efficiency. The energy conversion process is the result of a correlated motion of electrons and nuclei after photoexcitation, often under breakdown of the Born-Oppenheimer approximation. This talk is about ultrafast experiments aiming to resolve light induced molecular dynamics separately from the perspective of electronic structure and nuclear geometry. I will show a time resolved x-ray absorption experiment at the oxygen K-edge that gives us conclusive hints on ππ* - nπ* relaxation. In addition, I will show first experimental results from a gas phase ultrafast electron diffraction campaign resolving coherent nuclear wavepackets in small molecules. [1] Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules, J. Yang, M. Guehr, X. Shen, et al., Phys. Rev. Lett. 115, 173002 (2016) [2] Diffractive imaging of a rotational wavepacket in nitrogen molecules with femtosecond megaelectronvolt electron pulses, J. Yang, M. Guehr, T. Vecchione, et al., Nature Comm. 7, 11232 (2016)
Abstract