Ultracold chemistry and dipolar collisions in a quantum gas of polar molecules

Ultracold polar molecular quantum gases promise to open new research directions ranging from the study of ultra-cold chemistry, precision measurements to novel quantum phase transitions. Based on the preparation of high-phase space density gases of polar KRb molecules in the works of Ni et. al, the authors discussed the control of dipolar collisions and chemical reactions of polar molecules in a regime where quantum statistics, single scattering partial waves, and quantum threshold laws play a dominant role. In particular, the crucial role of electric dipole-dipole interactions and external confinement in determining the chemical reaction rate was pointed out. Finally, the prospects of reaching quantum degeneracy in bi-alkali samples of polar molecules and prospects for these systems as novel dipolar quantum many-body systems were discussed.