Quantum spin Hall states in graphene interacting with WS$_2$ or WSe$_2$

TL;DR

This study uses first-principles calculations to show that graphene interacting with WS$_2$ or WSe$_2$ monolayers can host quantum spin Hall states without magnetic fields, due to interface effects.

Contribution

It demonstrates the emergence of quantum spin Hall states in graphene when in contact with WS$_2$ or WSe$_2$, revealing a novel way to induce topological states.

Findings

Graphene's band structure is modified by WS$_2$ and WSe$_2$ interactions.

Quantum spin Hall states are observed without magnetic fields.

Interface effects induce topological states in graphene.

Abstract

In the framework of first-principles calculations, we investigate the structural and electronic properties of graphene in contact with as well as sandwiched between WS$_2$ and WSe$_2$ monolayers. We report the modification of the band characteristics due to the interaction at the interface and demonstrate that the presence of the dichalcogenides results in quantum spin Hall states in the absence of a magnetic field.