Independent Research Units

The main research interests are the structure and dynamics of hydrogen bonded, neutral clusters: methanol, ammonia, and water. The speciality of the group is the size selection of the clusters. Up to n=12 this is carried out by momentum transfer in collisions with rare gas atoms. For large clusters, the method of doping the clusters with sodium is applied. With these clusters ambitious spectroscopic experiments as well as scattering and dissociation processes have been measured. Very recently the transition to crystalline ice was observed at n=475. more

Many Systems in nature, especially complex systems, are characterized by several or even many typical length scales where different physical mechanisms are important. Dynamics on length scales inbetween the extrema of these characteristics is called "mesoscopic".
Examples of systems we study are electronic nano-structures with dynamics inbetween quantum and classical mechanics but also the wave propagation in correlated, weakly disordered media on length scales below the mean free path but above the wavelength and the intrinsic scales of the medium.
We explore universal mechanisms that lead to extreme events in systems that are so diverse as the electron dynamics in semiconductors, the sound transmission through turbulent media and the propagation of tsunamis in the ocean. more

Group funded by the Heisenberg program of the Deutsche Forschungsgemeinschaft

I am interested in structure formation, self organization, spontaneous symmetry breaking (in and out of equilibrium), and dynamic arrest with focus on the underlying microscopic processes. The physics of low dimensional systems is often more complex and possesses a richer variety of excited states compared to 3D systems. Examples range from Quantum Hall effect for 2D electron ensembles in MOSFET or Dirac cones in Graphene to classical systems and their phase transitions in 2D. more