Proximity-induced topological phases in bilayer graphene

TL;DR

This paper investigates how placing bilayer graphene on transition metal dichalcogenides can induce topological phases with potential spin Hall effects, offering tunable topological properties for experimental applications.

Contribution

It demonstrates the induction of topologically nontrivial phases in bilayer graphene via proximity effects, with classification using Z2 invariants and potential for tunability under gate voltage.

Findings

Induction of topological phases in bilayer graphene on TMDs

Identification of spin Hall effect potential

Possibility of tunable topological structures

Abstract

We study the band structure of phases induced by depositing bilayer graphene on a transition metal dichalcogenide monolayer. Tight-binding and low-energy effective Hamiltonian calculations show that it is possible to induce topologically nontrivial phases that should exhibit spin Hall effect in these systems. We classify bulk insulating phases through calculation of the Z$_2$ invariant, which unequivocally identifies the topology of the structure. The study of these and similar hybrid systems under applied gate voltage opens the possibility for tunable topological structures in real experimental systems.