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Research projects

The focus of our research lies in a deep fundamental understanding of matter and its quantum properties on the level of fundamental interactions among atoms and molecules and of electronic processes on the atomic scale. The properties of the systems under study and the dynamics of processes are primarily probed by the interaction with electromagnetic radiation. Utilized light sources include modern spectrally highly-resolving laser systems, ultra-short pulse lasers for dynamical studies and facility-based light sources in the XUV range (Synchrotrons, Free-Electron-Lasers).

In order to resolve quantum state specific properties, cold, controlled systems are probed in gas-phase atomic, molecular or cluster beams, trapped ensembles or cluster-isolated aggregates. This approach has the advantage of having isolated systems prepared in the gas phase with minimal environmental perturbations. The systems are very cold (few Kelvin to microKelvin temperatures) which gives us quantum state control and allows for high resolution spectroscopy. In particular, helium nanodroplet isolation techniques are pursued. On the one hand, we are intrigued by the quantum properties of superfluid helium nanodroplets and their guest-host interaction for which we use the embedded species as microscopic probes. On the other hand, we utilize the droplets as ''nano-cryostats'' for synthesizing nanostructures in a cold and weakly interacting matrix. In various projects questions ranging from fundamental physics and chemical reactivity to applied aspects in photovoltaics are investigated.

Overview of the probed systems

Figure 1: Overview of probed systems. a) Molecule inside superfluid helium nanodroplet, b) molecular aggregate inside helium nanodroplet, c) molecular network on the surface of solid rare gas cluster. The helium droplets and solid clusters are formed in supersonic jet expansion in vacuum. d) Atom/molecule beam colliding with trapped-atom target in a magneto-optical-trap.


Spectroscopy of isolated chromophore ensembles (SPICE)


Spectroscopy and imaging of photoelectrons and photoions in real-time (SAPPHIRE)


Phase-modulated nonlinear coherent spectroscopy (PHANCY)


Free electron laser research on atoms, molecules and clusters with high intensity XUV laser pulses (FERMI)


Coherent nonlinear spectroscopy in the EUV regime (CHOISE)

Penning en

Chemical reaction control at the quantum level (PENNING)


Ultra-fast dynamics in nanoplasmas (QUTIF)

Coherent multidimensional spectroscopy of controlled isolated systems (COCONIS)