LASER COOLING OF MOLECULES: TOWARDS ULTRACOLD SYMMETRIC AND CHIRAL SPECIES

Ultracold molecules are a promising platform for diverse scientific goals, ranging from quantum information and simulation to controlled chemistry and precision measurements of fundamental physics. The rich internal structure of molecules, including vibrations, rotations, and hyperfine interactions, provides many handles for exquisite control. However, the very same structural features that make molecules so desirable to study also complicate the task of \emph{controlling} a molecular species. Recently, laser cooling and magneto-optical trapping of diatomic molecules has been realized by several groups around the world, leading to temperatures as low as a few $\mu$K in long-lived, trapped samples of CaF. The ability to laser cool also allows for high fidelity detection of ultracold molecules and increases in phase space density allowing, e.g., the study of ultracold molecular collisions. As our group has shown with SrOH, these cooling methods apply to a broad and generic class of molecules, including polyatomic species which offer significant and qualitatively new advantages over any diatomic species. For example, polyatomic molecules may be fully polarized at extremely low electric fields and provide longer coherence times, allowing one to probe physics Beyond the Standard Model at the PeV scale. Importantly, the presence of these additional states in polyatomics does not interfere with the laser cooling process already observed in simpler species. In this talk, I will outline the experimental goal of creating ultracold gases of polyatomic molecules using illustrative examples from our laser cooling of CaF and SrOH molecules. I will also present how we will extend the techniques already demonstrated to chiral molecules, whose asymmetry presents novel challenges but also exciting new possibilities