A short overview on our research interests

The mutual interactions of atoms in condensed matter lead to a multitude of insulating, metallic, magnetic or superconducting states with novel collective excitations. Such behavior is often found in materials with partially filled d- or f-shells whose electrons cannot move independently from each other. Our research is dedicated to such correlated electron systems. Already small variation of the chemical composition, the magnetic field or an applied pressure enables to switch the ground state of these materials, e.g. insulating/metallic or magnetic/nonmagnetic. This leads to quantum phase transitions. We are investigating quantum states such as unconventional superconductivity, non-Fermi liquid or spin liquid phases, which are often found in the vicinity of such quantum phase transitions. While this is fascinating fundamental research, correlated electron materials are also promising candidates for the long-term future technological evolution, e.g. for electronic devices.


Blick ins Innere eines Ofens während der Einkristallzucht

Starting with sample synthesis and characterization, we are performing detailed investigations of the physical properties down to very low temperatures, under pressure and in high magnetic fields. A broad spectrum of methods is utilized for investigating, e.g. electrical resistivity, magnetic susceptibility, specific heat, thermal transport and thermal expansion. Further explorations of the microscopic and the dynamic properties of our samples are performed within various national and international collaborations.


Trennung von Einkristallen aus dem Flussmittel bei hohen Temperaturen in einer Zentrifuge

Our research is based upon single crystals which are synthesized by advanced methods, as well as epitaxial films, deposited as single layer or heterostructures. Utilizing optimized processes allows us to grow high-quality samples from a broad range of materials, whose structures could be controlled down to atomic scales. The films are structured with high resolution by optical or electron beam lithography and ionic etching applying modern clean room technology. Afterwards they are investigated with respect to electronic and magnetic properties.


Einsatz für unseren Mischungskryostat für Experimente bei Temperaturen zwischen 20 mK und 1 K (Photo um 90 Grad gedreht)