Folding Graphene into a Chern Insulator with Light Irradiation

Nano Lett. 2020 Aug 12;20(8):5860-5865. doi: 10.1021/acs.nanolett.0c01758. Epub 2020 Jul 21.

Abstract

Recently, the precise folding of flexible graphene is reported experimentally [ Science, 2019, 365, 1036-1040], demonstrating an efficient approach to manipulate its electronic and optoelectronic properties. Here, we propose a light-induced high-Chern-number Chern insulator (CI) in the folded graphene. Along both armchair and zigzag folding directions, we demonstrate that there are two-handedness-dependent chiral interface states localized at the curved region. Physically, they can be attributed to the light-induced mass-term inversion across the folded graphene. Most remarkably, by rationally designing the folding processes, 2D and 3D CIs are also realizable in a single-wall carbon nanotube and periodic folded graphene, respectively, illustrating a high tunability of the folding degree of freedom. We envision that this intriguing form of "foldtronics" will provide a new platform for investigating the topological state in 2D materials to draw immediate experimental attention.

Keywords: Chern insulator; chiral interface state; foldtronics; graphene; nanotube.