Spatially one-dimensional systems as e.g. spin chains or one-dimensional metals provide the opportunity for direct observation of the remarkable effects of strong quantum fluctuations. Quantum effects together with the low dimensionality lead to the absence of an ordered state of such systems even at low temperatures and hence render standard perturbative techniques for their investigation useless.
Among the remarkable phenomena of this type are the so-called 'spinon'-excitations in quantum antiferromagnets or the separation of charge and magnetic degrees of freedom in one-dimensional metals. The importance of the latter as a mechanism for high-Tc superconductivity is the topic of ongoing research efforts.
On the other hand the synthetization of new 'quasi-onedimensional' magnetic materials and the fabrication of semiconductor nano-devices ('quantum wires') provides experimental evidence for these phenomena.
These projects have been funded in parts through a Gerhard-Hess fellowship of the German Science Foundation (DFG). Furthermore the group is part of the federally funded graduate program 'Quantenfeldtheoretische Methoden in der Teilchenphysik, Gravitation, Statistischen Physik und Quantenoptik' in the Institut für Theoretische Physik.