Jin continued to advance the frontiers of ultracold science when she and her colleague, Jun Ye, managed to cool polar molecules that possess a large electric dipole moment to ultracold temperatures, also in 2008. Rather than directly cool polar molecules, they created a gas of ultracold atoms and then transformed them into dipolar molecules in a coherent way. This work led to novel insights regarding the chemical reactions near absolute zero. They were able to observe and control potassium-rubidium (KRb) molecules in the lowest energy state (ground state). They were even able to observe molecules colliding and breaking and forming chemical bonds. Jin's husband, John Bohn, who specialized in the theory of ultracold atomic collisions, collaborated with her on this work.