One-dimensional s-p superlattice
  The physics of one dimensional optical superlattices with resonant $s$-$p$ orbitals is reexamined in the language of appropriate Wannier functions. It is shown that details of the tight binding model realized in different optical potentials crucially depend on the proper determination of Wannier functions. We discuss the properties of a superlattice model which quasi resonantly couples $s$ and $p$ orbitals and show its relation with different tight binding models used in other works. 
Wojciech Ganczarek, Michele Modugno, Giulio Pettini, and Jakub   Zakrzewski
cond-mat.quant-gas hep-ph quant-ph