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Dynamical modulation (shaking) of ultracold atoms in an optical lattice allows the creation of tailored band structure which differs qualitatively from a free particle dispersion. A popular choice is the "double well" dispersion, which features two minima at inequivalent points of the (1D) Brillouin zone. With bosonic cesium atoms, this led to an interesting line of experiments showing spontaneous symmetry breaking via condensation in one of the two minima, with real-space phase separation into domains, analogous to a ferromagnet. With composite Feshbach molecules of lithium-6, we showed that the same dispersion led to a surprisingly rapid dynamic bifurcation in both real and momentum space, with generally short lifetime. Recently, we have succeeded in stabilizing these "split condensates" for longer times, allowing the magnetic field to ramp (and therefore the interactions to be tuned) during the resulting dynamics. This is exciting because a BCS analog of a BEC with condensation at multiple minima would be the famous FFLO (Fulde–Ferrell–Larkin–Ovchinnikov) state.
However, experiments so far reveal that, as the unitary limit is approached, the split nature of the condensate disappears. Several possible explanations for this will be discussed.