Cold Collisions

Ultracold systems consisting of dilute gases of atoms, ions or molecules enable a variety of controlled studies otherwise not possible. I will give a brief overview of how atoms are laser cooled, followed by our efforts in making ultracold LiRb molecules by associating Li and Rb atoms using a precisely tuned laser. We will see how the spectroscopic resolution improves drastically and how textbook knowledge of molecular physics can be used to produce ultracold molecules in a specific rovibrational state. I will then give a glimpse of an experiment where we put ultracold atoms in contact with relatively hot ions, trapped in a Paul trap. We will see two new results – light ions can be cooled by heavier atoms and resonant charge exchange offers an extremely efficient mechanism for ion cooling.