ABSTRACT
Trapping and cooling of neutral particles, starting 23 years ago with the first magnetic trapping of an atom [1], has completely transformed the toolbox of atomic, molecular, and optical physics. The breadth of scientific impact is astounding, ranging from the creation of new quantum systems, observation of new collisional processes, enhancements in precision measurement techniques, and new approaches to quantum information and simulation. However, we feel that the current situation is only a beginning. Compared to the situationwith atomic andmolecular beams, the number of trapped or cooled species is paltry-no more than 30 different species in comparison to hundreds for beams. With new species come new interactions (and new complications). There is much to look forward to. Examples of “unfinished business” include the creation of polar molecules in optical lattices (predicted to be useful as a tunable Hubbard model system), strongly interacting dipolar gases, dramatic improvements in the search for permanent dipole moments, in-laboratory study of the myriad of astrophysical cold collisional processes, quantum computers based on single atoms ormolecule qubits, and arbitrary species cooling for precision studies such as variation of fundamental constants (see Chapter 16 by Flambaum and Kozlov).All of these are on the near horizon, thanks to the continued large efforts toward expanding trapping and cooling techniques. The development of these new techniques and their rapid application to new systems has brought a continuing harvest of scientific findings.
