One-dimensional superlattices with s-p resonance

Abstract

We propose a realization of an extended Bose-Hubbard model, which takes into account next-nearest-neighbor tunneling, by one-dimensional double-well optical superlattice with a resonance between s and p orbitals in the neighboring sites. Custom method of finding maximally-localized Wannier functions enables us to compute physical tunneling coefficients, which put some restrictions on the studies of the model, what have recently been done using arbitrary values of parameters. Furthermore, it turns out that out of s-p resonance the system splits up into two disconnected lattices. We analyze also Zak-Berry phase and single-particle spectrum of the system. In order to present the problem in the full context, short review of rudiments of optical lattice physics and derivation of the standard Bose-Hubbard model is included.