Diffusive motion of C60 on a graphene sheet

TL;DR

This study investigates the diffusive behavior of a C60 molecule on a graphene sheet, revealing how the van der Waals potential influences its translational and rotational motion at finite temperature.

Contribution

It provides a combined theoretical and computational analysis of C60 motion on graphene, highlighting the effects of the periodic potential and characterizing diffusion in multiple directions.

Findings

C60 exhibits diffusive motion in lateral directions near graphene.

Perpendicular motion is diffusion in an effective harmonic potential.

C60 does not roll over the graphene sheet.

Abstract

The motion of a C60 molecule over a graphene sheet at finite temperature is investigated both theoretically and computationally. We show that a graphene sheet generates a van der Waals laterally periodic potential, which directly influences the motion of external objects in its proximity. The translational motion of a C60 molecule near a graphene sheet is found to be diffusive in the lateral directions. While, in the perpendicular direction, the motion may be described as diffusion in an effective harmonic potential which is determined from the distribution function of the position of the C60 molecule. We also examine the rotational diffusion of C60 and show that its motion over the graphene sheet is not a rolling motion.