Spin-filtered edge states in graphene

TL;DR

This paper reviews how various perturbations affect spin-filtered edge states in graphene, a material that could become a quantum spin Hall insulator due to spin orbit coupling, providing insights into topological insulators.

Contribution

It offers a comprehensive review of the effects of perturbations on spin-filtered edge states in graphene, enhancing understanding of topological insulator edge phenomena.

Findings

Perturbations like curvature and disorder influence edge state properties.

Edge reconstruction and orientation significantly affect spin-filtered states.

Coulomb interactions modify the electronic behavior of edge states.

Abstract

Spin orbit coupling changes graphene, in principle, into a two-dimensional topological insulator, also known as quantum spin Hall insulator. One of the expected consequences is the existence of spin-filtered edge states that carry dissipationless spin currents and undergo no back-scattering in the presence of non-magnetic disorder, leading to quantization of conductance. Whereas, due to the small size of spin orbit coupling in graphene, the experimental observation of these remarkable predictions is unlikely, the theoretical understanding of these spin-filtered states is shedding light on the electronic properties of edge states in other two-dimensional quantum spin Hall insulators. Here we review the effect of a variety of perturbations, like curvature, disorder, edge reconstruction, edge crystallographic orientation, and Coulomb interactions on the electronic properties of these spin filtered states.