Towards Strongly Correlated 2D Systems of Dipolar NaCs Molecules

We report on progress towards the creation of ultracold sodium-cesium molecules in their absolute ground state. NaCs molecules feature a large dipole moment of 4.6 Debye and are ideally suited for the creation of strongly interacting dipolar many-body quantum systems. We have made advances towards this goal on several frontiers: (1) We have created the first ultracold mixtures of sodium and cesium, including overlapping BECs of Na and Cs. (2) We have located and characterized Feshbach resonances between Na and Cs. (3) Using a Feshbach resonance at 864 G, we have created near-degenerate ensembles of NaCs Feshbach molecules at temperatures as low as 100 nK. (4) Finally, we have taken steps towards identification of a STIRAP pathway to the absolute ground state, including bound-bound precision spectroscopy of electronically excited molecular states and the construction of a phase-coherent STIRAP laser system. The goal of this project is the creation of strongly interacting dipolar 2D systems, for which a myriad of interesting phases is predicted, including the formation of supersolid phases and dipolar quantum crystals.