# First-principles study on the electronic and transport properties of periodically nitrogen-doped graphene and carbon nanotube superlattices

## TL;DR

This study uses first-principles calculations to explore the electronic and transport properties of periodically nitrogen-doped graphene and carbon nanotube superlattices, revealing nonmagnetic metallic behavior and quantized transmission spectra.

## Contribution

It provides a detailed first-principles analysis of nitrogen-doped superlattices, highlighting their electronic structure and transport characteristics, which were not previously characterized.

## Key findings

- All configurations exhibit nonmagnetic metallic behavior.
- Transmission spectra show quantized behavior under specific conditions.
- Periodic nitrogen doping creates stable superlattice structures with unique electronic properties.

## Abstract

Prompted by recent reports on $\sqrt{3} \times \sqrt{3}$ graphene superlattices with intrinsic inter-valley interactions, we perform first-principles calculations to investigate the electronic properties of periodically nitrogen-doped graphene and carbon nanotube nanostructures. In these structures, nitrogen atoms substitute one-sixth of the carbon atoms in the pristine hexagonal lattices with exact periodicity to form perfect $\sqrt{3} \times \sqrt{3}$ superlattices of graphene and carbon nanotubes. Multiple nanostructures of $\sqrt{3} \times \sqrt{3}$ graphene ribbons and carbon nanotubes are explored, and all configurations show nonmagnetic and metallic behaviors. The transport properties of $\sqrt{3} \times \sqrt{3}$ graphene and carbon nanotube superlattices are calculated utilizing the non-equilibrium Green's function formalism combined with density functional theory. The transmission spectrum through the pristine and $\sqrt{3} \times \sqrt{3}$ armchair carbon nanotube heterostructure shows quantized behavior under certain circumstances.