Markus Kowalewski - Coherent Signatures of Conical Intersections in Ultrafast X-Ray Spectroscopy
Mar 1, 2017
11:00 - 12:00
University of California, Irvine, USA
CFEL (Bldg. 99)
Seminar Room IV, O1.111
The rates and outcomes of virtually all photochemical and photobiological processes are dominated by conical intersections (CIs), which provide a fast sub-100-femtosecond nonradiative pathway back to the ground state. At a CI, the electronic and nuclear degrees of freedom frequencies are comparable and strongly mix due to the breakdown of the Born-Oppenheimer approximation.
A major challenge for their direct detection is
the rapidly varying gap between the electronic surfaces in their vicinity.
Modern XUV/X-ray light sources provide spectral broad and temporal short
pulses, which potentially allow for monitoring CIs directly. We present
theoretical studies on novel spectroscopic methods, which make use of
ultrashort X-Ray laser pulses.
The presented methods include Raman (TRUECARS),
time resolved photo electron spectroscopy and possible signatures of electronic
coherences in time resolved X-Ray diffraction.