Bulk topological proximity effect in multilayer systems

TL;DR

This paper explores how topological properties can be induced in multilayer systems through proximity effects, revealing nonlocal responses, the influence of layer arrangement, and the emergence of Dirac points.

Contribution

It demonstrates the bulk topological proximity effect in multilayer hexagonal systems and highlights the role of layer arrangement and nonlocal responses.

Findings

Topological properties can be induced in trivial layers via tunnel coupling.

Layer arrangement significantly affects the proximity effect.

The system exhibits semimetallic behavior with multiple Dirac points.

Abstract

We investigate the bulk topological proximity effect in multilayer hexagonal lattice systems by which one can introduce topological properties into a system composed of multiple trivial layers by tunnel coupling to a single nontrivial layer described by the Haldane model. This phenomenon depends not only on the number of layers but also on their arrangement, which can lead to the emergence of dark states in multilayer systems. The response of a trivial system to the proximity of a topological insulator appears to be highly nonlocal, in contrast to the proximity effect observed in context of superconductivity. Furthermore, for a wide range of parameters our system is semimetallic with multiple Dirac points emerging in the Brillouin zone.