Universality of moir\'e physics in collapsed chiral carbon nanotubes

TL;DR

This paper demonstrates that moiré patterns and magic angle phenomena are universally present in all chiral collapsed carbon nanotubes, with electronic properties similar to twisted bilayer graphene, through comprehensive computational analysis.

Contribution

It reveals the universal presence of moiré patterns and magic angles in all chiral collapsed nanotubes, expanding understanding of moiré physics beyond graphene.

Findings

All nanotube families exhibit unique moiré geometries.

Magic angles in nanotubes match those in twisted bilayer graphene.

Flat bands and localized states are identified across all types.

Abstract

We report the existence of moir\'e patterns and magic angle physics in all families of chiral collapsed carbon nanotubes. A detailed study of the electronic structure of all types of chiral nanotubes, previously collapsed via molecular dynamics, has been performed. We find that each family possesses a unique geometry and moir\'e disposition, as well as a characteristic number of flat bands. Remarkably, all kinds of nanotubes behave the same with respect to magic angle tuning, showing a monotonic behavior that gives rise to magic angles in full agreement with those of twisted bilayer graphene. Therefore, magic angle behavior is universally found in chiral collapsed nanotubes with a small chiral angle, giving rise to moir\'e patterns. Our approach comprises first-principles and semi-empirical calculations of the band structure, density of states and spatial distribution of the localized states signaled by flat bands.