Spin-1/2 fermions: crossover from weak to strong attractive interaction

Klaus Ziegler

Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany

The formation and dissociation of bosonic moelcules in an optical lattice, formed by spin-1/2 fermionic atoms, is studied in the presence of an attractive nearest-neighbor interaction. Three different phases are found at zero temperature: an empty, a condensed and a Mott-insulating phase. We measure the density of individual fermions (probably forming Cooper pairs) and the density of bosonic molecules.