Subwavelength vacuum lattices and atom-atom interactions in photonic   crystals
  We propose the use of photonic crystal structures to design subwavelength optical lattices in two dimensions for ultracold atoms by using both Guided Modes and Casimir-Polder forces. We further show how to use Guided Modes for photon-induced large and strongly long-range interactions between trapped atoms. Finally, we analyze the prospects of this scheme to implement spin models for quantum simulation 
A. Gonz\'alez-Tudela, C.-L. Hung, D. E. Chang, J. I. Cirac, H. J.   Kimble
quant-ph cond-mat.quant-gas