  Techniques to manipulate the individual constituents of an ultracold mixture
are key to investigating impurity physics. In this work, we confine a mixture
of the hyperfine ground states of Rb-87 in a double-well potential. The
potential is produced by dressing the atoms with multiple radiofrequencies. The
amplitude and phase of each frequency component of the dressing field are
individually controlled to independently manipulate each species. Furthermore,
we verify that our mixture of hyperfine states is collisionally stable, with no
observable inelastic loss.
