More is different
We are studying many-body phenomena at the interface between quantum optics and solid state physics.
Following a statement by P.W. Anderson, "More is Different", genuine many-body phenomena are emergent phenomena that only appear when many particles come together, typical examples being superfluidity or magnetism.
Ultracold Atoms in optical lattices
We study many-body phenomena using ultracold atoms, that is Bose-Einstein condensates and degenerate Fermi gases, which we load into optical lattices. These periodic optical potentials are analogous to the electrostatic potential felt by electrons in a conventional solid. Thereby, we effectively build a quantum simulator for condensed matter physics, where we can study many-body physics in a very clean and precisely controlled system and have all the tools from quantum optics at our disposal.
In particular, we can follow the dynamics of the system in real time and observe its non-equilibrium dynamics, which is typically an even richer problem than the equilibrium states.
In addition, this toolbox enables us to synthesize genuinely new many-body systems and create novel effects.
Disordered Systems / Many-body localization