Bose-Einstein condensate in gases of rare atomic species

We report on the successful extension of production of a Bose-Einstein condensate (BEC) to a rare atomic species. Despite its low natural abundance of 0.13%, Yb-168 is directly evaporatively cooled down to a BEC. Our successful demonstration encourages attempts to obtain quantum gases of radioactive atoms, which extends the possibility of quantum many-body physics and precision measurement. Moreover, a stable binary mixture of Yb-168 BEC and Yb-174 BEC is successfully formed.