Z_2 Topological Insulators in Ultracold Atomic Gases

TL;DR

This paper presents a method to realize Z_2 topological insulators in ultracold atomic gases using optical dressing, preserving time reversal symmetry, and introduces a new perspective from the nearly-free electron limit.

Contribution

It introduces a novel approach to engineer two- and three-dimensional Z_2 topological insulators in ultracold atoms via optical lattices and dressing techniques.

Findings

Constructed optical lattices for 2D Z_2 topological insulators.

Developed a general method for 3D Z_2 topological insulators.

Provided a new understanding of Z_2 insulators from the nearly-free electron perspective.

Abstract

We describe how optical dressing can be used to generate bandstructures for ultracold atoms with non-trivial 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.