The junior research group “Condensed Matter Physics with Cold Gases” investigates the low temperature properties of strongly correlated condensed matter systems in reduced dimensions. Quantum and thermal fluctuations are particularly strong in systems with reduced dimensionality and often mean-field like approaches fail. Mainly linear hydrodynamic approaches are used and effective methods beyond the linear hydrodynamics developed that will allow access to off-equilibrium dynamical properties of strongly correlated systems with internal degree of freedom-spin.

Ultra-cold atomic gases provide an ideal laboratory for thestudy of fundamental problems originally connected with strongly correlated condensed matter systems. The remarkable controllability of these systems allows the interference-free study of complex physics in a highly controllable way. The aim is to make predictions that could be tested in cold gas experiments and unveil poorly understood, strongly correlated phases of condensed matter systems ranging from one-dimensional spinor condensates to two-dimensional frustrated magnets. The effects of an external magnetic field on the Mott insulator phase of spin 1/2 fermions have been studied. Furthermore, the universality class of quantum phase transition induced by magnetic field in attractive spin 1/2 fermions has been described.