Complete control of the internal and external degrees of freedom of molecules is only possible in the ultracold regime. This kind of control has already been achieved with atomic species (ions and neutrals), leading to great progress in quantum computation, simulation, searches for physics beyond the standard model, novel collisions and chemical reactions. Ultracold molecules are a current frontier and experimental efforts with diatomic molecules have begun to pay off. The ultracold regime now has been reached with one class of species using atom association (heteronuclear and homonuclear bialkalis like KRb, RbCs, NaK) and another class of species using laser cooling (highly “diagonal” molecules, in particular SrF). Creating ultracold polyatomic molecules presents new laboratory challenges along with the promise to open up new territory in chemistry and physics.
I will describe work in our lab towards making ultracold gases of CaF as well as polyatomic moecules like SrOH and SrOCH3 or even larger species. One of our key long-term scientific goals is to achieve for polyatomic molecules the kind of single-state control now available with atoms (e.g. single internal quantum states in a single motional trap state), eventually with a very wide chemical variety of molecules. I will also give a brief overview of the potential impact of cold molecules in a variety of areas, including searches for new particle physics above the TeV level and ultraspecific chemical analysis for biological applications.