In this experiment we plan to laser cool polar molecules with closed electron shells that occupy singlet Sigma ground states. These molecules can have relatively simple internal structures that are favorable for laser-cooling and trapping. The electronic structure of these molecules is analogous to that of alkaline earth atoms, with both strong and weak optical transitions, ideal for applying large optical forces and narrow-line laser cooling respectively. Our singlet Sigma molecule of choice is aluminum monochloride (AlCl) which is expected to have an optical cycling transition at 261.5 nm. Our first step is to experimentally confirm this prediction before laser-cooling and trapping this species. Once cooled and trapped, these ultracold polar molecules will provide a unique setting for the development of quantum science via the manipulation of their large electric dipole moments, long-range interactions, strong couplings to external fields and rich internal structures. If you’d like to learn more about this research direction, please contact us here.