Dispersion Interaction of Atoms with Single-Walled Carbon Nanotubes described by the Dirac Model

TL;DR

This paper compares the Dirac and hydrodynamic models of graphene to calculate atom-nanotube interaction energies and forces, revealing that the Dirac model predicts stronger van der Waals interactions, especially for molecules.

Contribution

It introduces a method to compute atom-nanotube interactions using the Dirac model and compares results with the hydrodynamic model, highlighting differences in predicted forces.

Findings

Dirac model predicts larger van der Waals forces than the hydrodynamic model.

Hydrogen molecules exhibit stronger interactions than hydrogen atoms.

Numerical results show model-dependent variations in interaction energies.

Abstract

We calculate the interaction energy and force between atoms and molecules and single-walled carbon nanotubes described by the Dirac model of graphene. For this purpose the Lifshitz-type formulas adapted for the case of cylindrical geometry with the help of the proximity force approximation are used. The results obtained are compared with those derived from the hydrodymanic model of graphene. Numerical computations are performed for hydrogen atoms and molecules. It is shown that the Dirac model leads to larger values of the van der Waals force than the hydrodynamic model. For a hydrogen molecule the interaction energy and force computed using both models are larger than for a hydrogen atom.