of hopping. We show that due to these long-range interactions a destabilized stack of quasi-
one-dimensional Bose-Einstein condensates develops a correlated modulational instability
in the nonoverlapping sites. Interestingly, this density pattern may evolve spontaneously into
soliton filaments or into a checkerboard soliton crystal, offering a unique possibility to
observe such two-dimensional arrangements in ultracold gases. These self-assembled …