Identification of trivial and nontrivial insulators: Enhanced lateral shift in topological insulator-based cavity

Abstract

We theoretically exploit the parallel and perpendicular lateral shifts of topological insulator slab by using stationary-phase approach. Compared with ordinary insulators, the perpendicular lateral shift of topological insulator exhibits unusual features, which provides a promising approach to differentiate these two phases. Furthermore, it is found that the perpendicular lateral shift of topological insulator is a surface-sensitive parameter and can be used to extract its surface characteristics. Additionally, a topological insulator-based cavity structure is proposed to remarkably enhance the lateral shift due to the localized defect mode, which enables better observation of the lateral shift in the experiment.