One-dimensional s-p superlattice

TL;DR

This paper reexamines the physics of one-dimensional optical superlattices with resonant s-p orbitals, emphasizing the importance of Wannier functions in accurately modeling their tight binding properties.

Contribution

It clarifies how the proper determination of Wannier functions affects the tight binding models of s-p superlattices and relates different models in the literature.

Findings

Proper Wannier functions are crucial for accurate tight binding models.

The superlattice model couples s and p orbitals near resonance.

Relations between different tight binding models are established.

Abstract

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.