ABSTRACT
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463
The realization of Bose-Einstein condensates (BEC) and quantum degenerate Fermi gases with cold atoms has been one of the highlights of experimental atomic physics during the last decade [1]. In view of recent progress in the experimental work on the production of cold molecules we expect a similarly spectacular
development for molecular physics [2-22]. The outstanding features of the physics of cold atomic and molecular gases are the microscopic knowledge of the manybody Hamiltonians, as realized in the experiments, combined with the possibility to control and tune system parameters via external fields. External field control can be achieved by confining ultracold gases with magnetic, electric and optical traps, allowing for the formation of quantum gases in one-, two-, and threedimensional geometries, and tuning contact interparticle interactions by varying the scattering length via Feshbach resonances [23,24]. This control is key to the experimental realization of fundamental quantum phases, as illustrated by the BECBCS (Bardeen-Cooper-Schrieffer) crossover in atomic Fermi gases [25-29], the Kosterlitz-Thouless transition [30-32] and the superfluid Mott insulator quantum phase transition with cold bosonic atoms in an optical lattice [33,34]. A recent highlight has been the realization of a degenerate magnetic dipolar gas of 52Cr atoms [35-37].
