K. Honda

Bose‐Einstein Condensation of Yb atoms

We could recently achieve the Bose Einstein condensation (BEC) of Yb atoms. Yb differs from most of the elements that have previously been condensed, because it is a two‐electron atom with the singlet S ground state. Furthermore the Bosonic isotopes of Yb, like 174Yb which we succeeded to condensate, has no nuclear spin, so that the ground state is completely spin‐less state and hence insensitive to magnetic fields. Thus a new type of atom could join the group of atoms for BEC studies. We would like to report how we could achieve the BEC of Yb atoms.

BOSE-EINSTEIN CONDENSATION OF YTTERBIUM ATOMS

We report the achievement of Bose-Einstein condensation of ytterbium (Yb) atoms by the all-optical method. The Yb atomic beam from an oven is first decelerated by the Zeeman slowing technique using the singlet transition and then captured by a magnetooptical trap using an intercombination transition. The evaporative cooling is performed in a novel crossed optical trap, which results in the formation of condensates of about 5 x 10 3 atoms of 174 Yb. We determine the scattering length of 174 Yb to be between 1 and 3 nm by combining the behavior of the condensate and the result of measuring photoassociation. The prospect of Yb condensates is also discussed.