Dispersion Interactions between Optically Anisotropic Cylinders at all Separations: Retardation Effects for Insulating and Semiconducting Single Wall Carbon Nanotubes

TL;DR

This paper derives a comprehensive model for van der Waals dispersion interactions between anisotropic cylindrical nanostructures, including retardation effects, and applies it to single-walled carbon nanotubes at all separations and orientations.

Contribution

It presents a complete formulation of dispersion interactions between anisotropic cylinders, incorporating retardation effects, and applies it specifically to carbon nanotubes.

Findings

Dispersion interactions can be repulsive under certain conditions.

Interactions are non-monotonic with respect to separation and orientation.

Retardation effects significantly influence the interaction strength.

Abstract

We derive the complete form of the van der Waals dispersion interaction between two infinitely long anisotropic semiconducting/insulating thin cylinders at all separations. The derivation is based on the general theory of dispersion interactions between anisotropic media as formulated in [J. N. Munday, D. Iannuzzi, Yu. S. Barash and F. Capasso, {\sl Phys. Rev. A} {\bf 71}, 042102 (2005)]. This formulation is then used to calculate the dispersion interactions between a pair of single walled carbon nanotubes at all separations and all angles. Non-retarded and retarded forms of the interactions are developed separately. The possibility of repulsive dispersion interactions and non-monotonic dispersion interactions is discussed within the framework of the new formulation.