Sympathetic cooling in an optically trapped mixture of alkali and spin-singlet atoms

Phys Rev Lett. 2011 Apr 15;106(15):153201. doi: 10.1103/PhysRevLett.106.153201. Epub 2011 Apr 11.

Abstract

We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of 6Li by 174Yb and extract the s-wave scattering length magnitude |a(6Li-174Yb)|=(13±3)a0 from the rate of interspecies thermalization. Using forced evaporative cooling of 174Yb, we achieve reduction of the 6Li temperature to below the Fermi temperature, purely through interspecies sympathetic cooling.