Z(2) topological insulators in ultracold atomic gases.

We describe how optical dressing can be used to generate band structures for ultracold atoms with nontrivial Z(2) topological order. Time-reversal symmetry is preserved by simple conditions on the optical fields. We first show how to construct optical lattices that give rise to Z(2) topological insulators in two dimensions. We then describe a general method for the construction of three-dimensional Z(2) topological insulators. A central feature of our approach is a new way to understand Z(2) topological insulators starting from the nearly free electron limit.