Tuning the topological winding number by rolling up graphene

TL;DR

This paper theoretically shows that rolling graphene into nanoscrolls and applying a magnetic field can precisely tune the topological winding number, significantly enhancing conductance and enabling the design of topological materials.

Contribution

It introduces a method to control the topological winding number in graphene nanoscrolls, linking geometry and topology to tune electronic properties.

Findings

Conductance can be enhanced by a factor of N in N-turn nanoscrolls.

Magnetoconductance is positively tunable via the winding number.

Maximum winding number increases conductance proportionally.

Abstract

Nanoscrolls, radial superlattices formed by rolling up a nanomembrane, exhibit distinct electronic and magneto-transport properties compared to their flat counterparts. In this study, we theoretically demonstrate that the conductance can be precisely enhanced N times by rolling up graphene into an N-turn nanoscroll and applying a longitudinal magnetic field. This tunable positive magnetoconductance stems from the topological winding number which is activated in a carbon nanoscroll with magnetic flux and its maximum value purely increases with the scroll winding number (the number of turns). By integrating material geometry and topology, our work opens the door to artificially creating, customizing, and designing topological materials in rolled-up graphene-like systems.