Two Atoms in a Double Well: An Exact Solution
  We propose to experimentally realize an odd parity eigenstate $\left\vert b\right\rangle $ of two atoms in the double well. The occupation probability of this state shows evident dependence on the interaction, distinct from the result of two-mode model adopted in the Heidelberg experiment. The tunneling dynamics of two atoms starting from the $NOON$ state with infinite barrier height can be derived from the exactly solved model of $\delta $-barrier split double well based on a Bethe ansatz type hypothesis of the wave functions. We find that the single particle tunneling transfer the probabilities between double occupancy and single occupancy of each well. 
Yanxia Liu, Yunbo Zhang
cond-mat.quant-gas quant-ph