Quantum mechanics predicts that electrons in a solid or atoms in a gas can loose their single-particle properties completely and instead start behaving collectively. This often leads to the emergence of new states of matter which are a fascinating topic for fundamental research and offer the potential for technological advances. Important examples include high-temperature superconductivity in cuprates and iron pnictides, quantum wires such as carbon nanotubes, as well as the Bose-Einstein condensation in trapped atomic gases at ultracold temperatures.
The research interests of our group lie in the theoretical explanation of the physics of such strongly correlated quantum systems. Recent publications include work on
Our research on these topics often combines analytical methods (Bethe ansatz, bosonization, conformal field theory, nonlinear sigma-models, renormalization group) with numerical methods, in particular, the density-matrix renormalization group (DMRG). We have developed several new DMRG-type algorithms to study quantum dynamics both in equilibrium at finite temperatures and in non-equilibrium following a quantum quench.