Topological Phase Diagram of BiTeX--Graphene Hybrid Structures

TL;DR

This paper theoretically demonstrates how strain can induce topological phase transitions in graphene-BiTeX heterostructures, potentially enabling experimental realization of topological insulators with engineered band structures.

Contribution

It introduces a method to control the topological phase of graphene-BiTeX systems through strain, highlighting the role of inherent structural stress in phase transitions.

Findings

Strain can tune the topological phase of graphene-BiTeX heterostructures.

Structural stress may induce a topological phase transition.

Potential for experimental realization of topological insulators.

Abstract

Combining graphene with other novel layered materials is a possible way for engineering the band structure of charge carriers. Strong spin-orbit coupling in BiTeX compounds and the recent fabrication of a single layer of BiTeI points towards a feasible experimental realization of a Kane--Mele phase in graphene-based heterostructures. Here, we theoretically demonstrate the tunability of the topological phase of hybrid systems built from graphene and BiTeX (X = I, Br, Cl) layers by uniaxial in-plane tensile and out-of plane compressive strain. We show that structural stress inherently present in fabricated samples could induce a topological phase transition, thus turning the sample in a novel experimental realization of a time reversal invariant topological insulator.