Quasipure Bose-Einstein Condensate Immersed in a Fermi Sea

We report the observation of coexisting Bose-Einstein condensate (BEC) and Fermi gas in a magnetic trap. With a very small fraction of thermal atoms, the ⁷Li condensate is quasipure and in thermal contact with a ⁶Li Fermi gas. The lowest common temperature is 0.28 μK~=0.2(1)T_C = 0.2(1)T_F where T_C is the BEC critical temperature and T_F the Fermi temperature. The ⁷Li condensate has a one-dimensional character.