The correlated electron dynamics of doubly excited states in helium can be controlled with strong fields, state resolved via transient absorption spectroscopy. Nonlinear absorption spectroscopy with intense XUV FEL pulses gives access to phase shifts due to dressed-state dynamics.
We perform attosecond transient absorption spectroscopy (8-fs-visible pump, 200-as-XUV probe) to measure nonadiabatic dynamics of iodine monobromide. The results visualize the switching of unoccupied-orbital character from $\sigma^{*}$ to $\pi/\pi^{*}$ ensuing at the avoided crossing.
We investigate transient (2.4-fs time scale) coherence effects imprinted on the electronic level structure of the doubly-charged neon ion caused by the nonlinear interaction with intense extreme-ultraviolet free-electron-laser radiation under the influence of its stochastic time structure.
Using attosecond transient absorption (ATAS), core-excited state lifetimes of iodine monochloride are retrieved, with additional detail about the orientation of the core excited state orbital relative to the bond direction.
Using high pulse energy soft X-ray attosecond pulses, we investigate ultrafast molecular photoionization and Auger emission dynamics near and beyond the O $K$-edge of NO via angular streaking with a co-linear velocity map imaging spectrometer.
The ultrafast evolution of a molecule following ionisation in a strong laser field is a central problem in attosecond science. Here we extend the method of high harmonic generation spectroscopy (HHGS) to extracting these dynamics in a way that is robust and general.
