UConn Physics Colloquium
Ultracold Molecules and the Mott Insulator Phase Transition
University of Texas, Austin
Experiments with ultracold gases have demonstrated an ever-increasing degree of control over atomic degrees of freedom. For example, by loading a Bose-condensed gas into an optical lattice, it is now possible to drive a transition between the Bose-condensed phase and a Mott insulating phase. In the insulating phase, an integer number of atoms occupies each lattice site with an exactly specified translational wavefunction. Further, recent experiments have also demonstrated that Feshbach resonances or Raman photoassociation of atoms in ultracold gases can produce a gas of state-selected, ultracold molecules. We describe new experiments in which we have demonstrated the formation of a Rb Mott insulator phase with exactly two atoms per site, and driven coherent Raman photoassociation transitions in this phase. This allows us to interconvert between an atomic and molecular Mott insulator phase, and to demonstrate almost perfect reversibility in a photoassociation process for the first time. We will also describe related photoassociation experiments in laser-cooled gases and in Bose condensates, that have allowed us to study ultracold atom-molecule collision processes. These experiments demonstrate an unprecedented degree of control over atomic recombination and molecular dissociation processes, and should allow us to carry out investigations of molecular quantum gases.
Friday, November 14, 2003
(Refreshments will be served immediately following the colloquium in the lobby outside the lecture hall)