We have performed high-resolution spectroscopy using ultracold ytterbium(Yb) atoms. Yb is a rare-earth atom and has the two valence electrons, which results in the singlet and triplet states connected by extremely narrow intercombination transitions 1S-3P. Yb has another distinct feature of the existence of rich varieties of stable isotopes of five bosons and two fermions, which allows us to study various interesting quantum degenerate gases of Yb atoms. Recently we have performed high-resolution two-color photo-association spectroscopy to determine the binding energies of least bound states of six isotopes of Yb. Based on these measurements and theoretical considerations, we have accurately determined the scattering lengths of all Yb isotopes as well as those of different isotope pairs. The obtained scattering lengths are consistent with the behaviors of our successfully obtained BECs of 174Yb, 170Yb, and 176Yb, and can also explain efficient evaporative cooling which results in Fermi degeneracy of 6 spin mixtures of 173Yb and 174Yb-173Yb quantum degenerate mixture. In addition, we have performed high-resolution laser spectroscopy of BEC and Fermi degenerate gases using ultra-narrow intercombination transitions 1S0-3P0 and 1S0-3P0. In the talk, we will describe the details about these experiments in addition to the recently performed optical Feshbach resonance experiment. The possible application of cold Yb atoms in an optical lattice to a scalable quantum computation will be also discussed.
10 Minute Talk: Scattering without Decoherence