Experiments with dispersion engineered Bose-Einstein condensates: Raman dressing and novel optical lattices

This thesis aims at the investigation of complex condensed matter phenomena using quantum degenerate ultra-cold atomic gases as a well-controlled model system. The phenomena range from a novel spin-momentum coupling and periodic optical potentials, to mean field anti-ferromagnetic like ordering. Additionally the status of the implementation of a novel multi-dimensional optical super-lattice is reported. The first set of experiments presented in this thesis employ a Raman dressing scheme to realize spin-orbit coupling in a BEC. An understanding of the dynamic processes associated with this coupling is developed starting from the single particle level. After this, the many body ground state of the system is investigated and is found to provide an intriguing mapping to the Dicke model known from quantum optics. Next, the Raman dressing is combined with a weak moving optical lattice. This leads to a more complex band structure that is experimentally probed by exciting dynamical instabilities of the system. The combination of the Raman dressing with optical lattices has the potential to realize systems with large effective magnetic flux and novel phases. Finally, following a previous line of research in the WSU BEC group, novel dynamics due to the spatial Rabi winding of an elongated two-component BEC are presented. The experiments are conducted with an experimental apparatus built at WSU. To facilitate the studies of this thesis, a number of new tools have been installed in the setup, such as multi-dimensional optical lattices, precision magnetic field control, and a Raman laser system. Details of these technological advances will be described together with the scientific results that they have enabled.