TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/31798/
KW  - Attosekundenspektroskopie
KW  -  Femtosekundenspektroskopie
KW  -  transiente Absorptionsspektroskopie
KW  -  ultrakurze Laserpulse
KW  -  hohe harmonische Erzeugung
KW  -  XAS
KW  -  TR-XAS
KW  -  ATAS
CY  - Heidelberg
TI  - Ultrafast Laser Control of Molecular Quantum Dynamics from a Core-Electron Perspective
ID  - heidok31798
AV  - public
Y1  - 2022///
A1  - Rupprecht, Patrick Dominik
N2  - This work introduces two experimental approaches to control quantum dynamics in molecules, employing core electrons as messengers. A laser source providing ultrashort pulses has been developed to access the timescale of electronic and structural dynamics inside molecules. Pulses of few-cycle durations in the 1 ?m to 2 ?m short-wavelength infrared (SWIR) spectral region provide intensities up to 10^15 W/cm^2. In combination with a vacuum beamline, this experimental setup
allows for ultrafast laser control of molecular dynamics probed by core-electron
transitions via x-ray absorption spectroscopy (XAS). The first experiment investigates the manipulation of molecular electronic structure. Here, a soft x-ray (SXR) pulse probes simultaneously to an SWIR pulse of variable intensity. The measured intensity dependent absorbance changes in SF6 reveal an increased effective electronic-exchange energy. This demonstrates the alteration of this purely quantum-mechanical component of the electron-electron interaction for the first time. In a second experiment, an SWIR pulse induces coherent molecular vibrations with amplitudes of ten times the diameter of the nucleus. Subsequently, a time-delayed SXR pulse probes the bond-length changes via core-level transitions. This enables an unprecedented 14 femtometer precision which paves the way for site-specific vibrational metrology in gas-phase molecules. Overall, these results enable ultrafast chemical control on a quantum level.
ER  -