  Modeling strongly correlated atoms demonstrates the possibility to prepare
quantum superpositions that are robust against experimental imperfections and
temperature. Such superpositions of vortex states are formed by adiabatic
manipulation of interacting ultracold atoms confined to a one-dimensional ring
trapping potential when stirred by a barrier. Here, we discuss the influence of
non-ideal experimental procedures and finite temperature. Adiabaticity
conditions for changing the stirring rate reveal that superpositions of many
atoms are most easily accessed in the strongly-interacting, Tonks-Girardeau,
regime, which is also the most robust at finite temperature. NOON-type
superpositions of weakly interacting atoms are most easily created by
adiabatically decreasing the interaction strength by means of a Feshbach
resonance. The quantum dynamics of small numbers of particles is simulated and
the size of the superpositions is calculated based on their ability to make
precision measurements. Experimental creation of strongly correlated and
NOON-type superpositions with about 100 atoms seems feasible in the near
future.
