High-Chern-number bands and tunable Dirac cones in $\beta$-graphyne

TL;DR

This paper explores how spin-orbit couplings in $eta$-graphyne can produce high-Chern-number bands and tunable Dirac cones, offering a platform for topological phases with controllable properties.

Contribution

It demonstrates that intrinsic and Rashba spin-orbit couplings in $eta$-graphyne enable tunable topological bands and Dirac cones, revealing rich spin-orbit physics in this material.

Findings

Intrinsic spin-orbit coupling yields high- and tunable Chern-number bands.

Rashba spin-orbit coupling controls Dirac cone position and number.

Potential realization of topological and Chern insulators in $eta$-graphyne.

Abstract

Graphynes represent an emerging family of carbon allotropes that recently attracted much interest due to the tunability of the Dirac cones in the band structure. Here, we show that the spin-orbit couplings in $\beta$-graphyne could produce various effects related to the topological properties of its electronic bands. Intrinsic spin-orbit coupling yields high- and tunable Chern-number bands, which may host both topological and Chern insulators, in the presence and absence of time-reversal symmetry, respectively. Furthermore, Rashba spin-orbit coupling can be used to control the position and the number of Dirac cones in the Brillouin zone. These findings suggest that spin-orbit-related physics in $\beta$-graphyne is very rich, and, in particular, that this system could provide a platform for the realization of a two-dimensional material with tunable topological properties.