Helium diffraction on SiC grown graphene, qualitative and quantitative description with the hard corrugated wall model

TL;DR

This paper compares a simplified hard wall model with ab initio calculations to analyze helium diffraction on graphene grown on SiC, providing a qualitative and quantitative understanding of the surface structure.

Contribution

It introduces a complementary approach using the hard wall model to interpret helium diffraction data without prior assumptions, validated against exact calculations.

Findings

Hard wall model provides accurate qualitative insights.

Quantitative agreement with ab initio calculations is demonstrated.

Simplified approach enhances surface structure analysis.

Abstract

The Moir\'{e} structure of epitaxial graphene mono layer grown on 6H-SiC(0001) has been investigated recently by grazing incidence fast atom diffraction, and the results were compared with the calculation of the structure \textit{ab initio} and exact diffraction codes. We review these results and present a complementary approach using the Hard Wall Model to extract information without any \textit{a priori}. Reversely, taking advantage of previous exact calculations we evaluate quantitatively the performance of this simplified approach by comparing predictions using the same potential energy surface.